The Ultimate List of 550+ Spam Filter Keywords and Trigger Words to Avoid in 2023 - Mystrika

Navigating spam filters to reach the inbox is an epic journey only the mightiest email warriors can ace. Do you have the skills to avoid dangerous spam trigger words and deliver your message?

This grand quest begins by vanquishing the foulest of keywords, before grappling with fierce inbox guardians, and finally…emerging victorious with loyal recipients cheering your triumph.

Okay, maybe that’s a bit over the top. But avoiding email spam filters is critical, and this guide will equip you for the mission.

Let’s dig into how filters work, 550+ problematic spam words to avoid, and pro tips for improving your deliverability. Onward to inbox glory!

Page Contents

Understanding Spam Filters and Trigger Words

Email is an invaluable communication tool, but it can also be abused by spammers and scammers. Thankfully, email providers have spam filters that act as automated gatekeepers to keep unwanted messages out of our inboxes. However, these filters aren’t perfect. Sometimes legitimate emails get flagged as spam simply for using particular words or phrases. Let’s break down how spam filters work and why certain spam trigger words cause issues.

What are spam filters and how do they work?

Every major email provider—Gmail, Outlook, Yahoo, etc.—uses automated spam filters to detect and divert spammy or dangerous emails away from users’ inboxes.

Email providers use automated spam filters

These filters are software programs that analyze the content and attributes of each incoming email to determine whether it’s legitimate or spam. The filter gives each email a “spam score” based on what it finds. If the score crosses a certain threshold, the email is sent to the spam folder. Otherwise, it lands in the inbox as normal.

Spam filters check emails incredibly quickly, processing billions of messages every day. They use artificial intelligence and machine learning to get better at detection over time. However, no spam filter is 100% accurate.

Spam filters scan emails for “red flags”

So how do spam filters decide which emails look potentially suspicious or malicious? Here are some of the most common “red flags” they look for:

Use of certain words and phrases (more on this below!)
Unnatural wording and strange phrases
ALL CAPS and excessive punctuation!!!!!
Embedded images and unsafe attachments
Invalid sender address or spoofed sender name
Suspicious links to dodgy websites
Lack of unsubscribe option (against CAN-SPAM law)
Attempts to disguise links or URLs

Common “red flags” that trigger spam filters

If an email contains too many shady attributes like these, the spam filter will automatically move it to the spam folder before the user even sees it. Quite clever, these machines!

Some sneaky spam techniques like image-based text and embedding emails within PDFs can outwit filters. So while users don’t have to wade through obvious low-quality spam, more advanced junk can slip into the inbox on occasion.

What are spam trigger words and why do they cause issues?

Now that we know how spam filters work in general, let’s talk specifically about spam trigger words.

Definition of spam trigger words

Spam trigger words are certain keywords and phrases that commonly appear in spam emails. As a result, they tend to automatically trigger spam filters and cause emails to be flagged as junk.

These problematic terms typically fall into a few main categories:

Words that create a false sense of urgency or pressure
Exaggerated claims and “too good to be true” offers
Financial and money-related terminology
Jargon, legalese, and other unnatural wording
References to questionable products, services, or behaviors

Main types of problematic spam trigger words

Here are some examples of typical spam trigger words in each category:

Urgency: Act Now, Last Chance, Claim Your Prize, Don’t Miss Out!
Exaggeration: Free Gift, Earn Millions, Instant Results, Strongest Ever
Financial: Cash Bonus, Credit Score, Debt Relief, Best Rates
Jargon: As per, Kindly, Regarding, Compliance
Questionable: Casino, Singles, Foreign Pharmacy, Lose Weight Fast

You probably noticed some of these eye-roll-inducing phrases in spammy emails that somehow bypass filters and reach your inbox. But why exactly do these particular words and phrases tend to trigger spam filters?

Why spam words can cause deliverability problems

There are three main reasons why the use of certain spam trigger words can tank your email deliverability:

These words and phrases tend to appear frequently in reported spam. Spam filters look for patterns in messages people mark as spam to better detect junk in the future. So if 10,000 spammers used “Act Now!” in their email subject lines last month, and recipients reported those emails as spam, filters will start flagging other emails with “Act Now!” in the future.
Too many hype-words or salesy claims in one message look inauthentic. While a single “Call to Action!” button on your email might be fine, sounding constantly high-pressure and promotional is a red flag. Spam filters assume legitimate emails will use more natural language.
Certain industries like finance, pharmaceuticals, and gambling contain jargon that spammers love to misuse. So filters automatically treat their terminology as suspicious to separate the scams from legitimate companies.

The bottom line is you want to write emails that sound like a helpful human, not an overly-eager salesbot. Avoiding frequently abused spam trigger words is a smart way to stay off spam filters’ blacklists.

So that covers the basics of how spam filters work and why you should keep your email content free of obvious spammy language. Next, let’s go over a list of 550+ specific spam words and phrases that you may want to avoid—or at least use carefully and intentionally—in your own email marketing.

Comprehensive List of 550+ Spam Trigger Words to Avoid

Now we come to the fun part – let’s go through an extensive list of over 550 specific spam trigger words and phrases that you may want to use with caution in your own emails.

These problematic terms typically fall into five main categories:

Words that create false urgency or pressure

Spam filters don’t like seeing high-pressure language that pushes readers to take immediate action. Here are some common examples:

Act now!
Apply here
Become a member
Buy direct
Buy today
Call now!
Claim your prize
Deal ending soon
Don’t delete
Don’t hesitate
Don’t miss out!
For instant access
Get it now
Hot price
Hurry!
Immediately
Instant access
Last chance
Limited time only
New customers only
Now only!
Once in a lifetime
Order now
Please reply
Purchase today
Right now
Sale ending soon
Seize the opportunity
Sign up free today
Supplies are limited
Take action now
This won’t last
Today only
Top urgent
Urgent response needed
What are you waiting for?
While supplies last
You have been selected
Your instant access password

Phrases that overpromise or exaggerate claims

Using hype language that sounds too good to be true is another spam trigger. For example:

#1 rated
100% free
100% satisfied
Be your own boss
Best bargain
Big bucks
Cash bonus
Drastically cut your costs
Eliminate your debt
Expect to earn
Finally pay off your credit cards
Free bonus
Free consultation
Free gift
Free hosting
Free installation
Free investment
Free leads
Free membership
Free money
Free priority mail
Get out of debt
Giving it away
Grow your business fast
Guaranteed
Highest paying
Increase sales fast
Increase traffic overnight
Join millions
Last a lifetime
Limitless earnings
Lowest price ever
Make money now
Miracle cure
Never pay a bill again
Once in a lifetime
One hundred percent guaranteed
Pennies a day
Potential earnings
Revolutionary product
Risk free
Satisfaction guaranteed
Slash your mortgage
Solve all your problems
Unlimited
Unsecured credit
You’re a Winner!

Terms that relate to questionable or unethical behavior

Spam filters watch for language associated with unethical, illegal, or “too good to be true” offers:

Avoid bankruptcy
Cancel at any time
Cashcards accepted
Certified pre-owned
College diploma
Credit bureaus
Cures baldness
Dig up dirt
Eliminate debt
Financial freedom
Foreclosure rescue
Free laptop
Full refund
Growth hormone
Human growth hormone
Lose weight fast
Lower interest rates
Lower monthly payment
Luxury watch
Male enhancement
Meet singles
Multi-level marketing
Nigerian
No age verification
No credit check loans
No experience needed
No hidden costs
No inventory
No investment
No medical exams
No obligation
No purchase required
No questions asked
No selling required
Online pharmacy
Order status
Passwords
Purchase chea
Request more info
Rolex watch
Score with babes
Social security number
Stainless steel
Stop foreclosure
Stop paying rent
Teen
Trial offer
Undisclosed
Unsecured debt
US dollars
User password
While you sleep
Wife
Work from home

Financial keywords that can seem suspicious

Terms related to money, investment, banking, and credit often appear in phishing scams and other financial spam:

0% APR
Accept credit cards
Bad credit
Bank statement
Best rates
Cash
Cash bonus
Credit
Credit bureaus
Credit card offers
Credit or debit
Debt relief
Earn per week
Easy income
Extra income
Finances
Financial
Home equity line
Income
Increase revenue
Lower interest rate
Lower monthly payments
Lowest insurance rates
Money back guarantee
Mortgage rates
No fees
Offshore
Pre-foreclosure
Pure profit
Quotes
Reduce debt
Reduce taxes
Refinance home
Rent to own
Serious cash
Slash your debt
Subject to credit
Unsecured credit

Jargon and other unnatural wording

Stilted, old-fashioned, or oddly-worded phrases also trigger filters’ “spam radar”:

As per
Billing address
Dear friend
Enhance your
Kindly
Mail in order form
Message contains
Multi-level marketing
No disappointment
No experience needed
No-obligation
Obligation
Online business opportunity
Prizes
Rebate
Refunds
Removal instructions
Regarding
Reserves the right
Sent in compliance
This isn’t spam
Vacation offers
Warranty
Web traffic
While stocks last

So in summary, hundreds of spam trigger words exist that can potentially tank your email deliverability if overused. Always double check that your email’s language sounds natural and avoids pushy sales lingo.

Next let’s go over some pro tips for improving deliverability and avoiding landing in spam folders, regardless of any particular spammy words you may use.

Pro Tips for Avoiding Spam Filters and Improving Deliverability

Avoiding obvious spam trigger words is a good start, but not a guarantee your emails will reach the inbox. Let’s go over some additional pro tips and best practices for improving deliverability.

Check for spam words using online tools

The first line of defense is to run your email content through a spam check before sending your campaign. Here are some handy online spam check tools:

MailTester – This free tool gives you a spam score from 1 to 10 and highlights any spammy phrases it finds.
Postmark SpamCheck – Postmark analyzes your email’s content and subject line to detect issues.
EmailMarker – This spam checker flags urgent language, spammy words, and other attributes.
MailChimp Spam Trigger Words – MailChimp built a tool that searches for their list of 300+ problematic spam words.

These tools scan your email content and subject line to identify any potential red flags BEFORE you hit send and risk landing in recipients’ spam folders. Look for urgent wording, ALL CAPS, excessive repetition of words, odd phrases, and other questionable elements.

If you get feedback that an email looked too “salesy” or ended up in spam, run it through these tools to identify what may have caused issues. Then you can refine your language for future communications.

Keep your email lists clean and engaged

Beyond writing great content, having a quality email list improves your sender reputation with ISPs and reduces the chances of spam misclassifications. Here are some list management best practices:

Remove inactive subscribers – Export your list and delete contacts that haven’t opened an email in 6 months or longer. Focus on kept your list engaged rather than massive.
Avoid purchased email lists – Buying lists of unvetted, unrelated email addresses is a recipe for low engagement and spam complaints. Stick to contacts who know your brand.
Use double opt-in forms – Require subscribers to confirm their email address before being added to your list. This filters out fake/invalid addresses.
Personalize and segment content – Send relevant messages tailored to subscribers’ interests to drive higher open and click rates.
Monitor engagement metrics – Track open and click-through rates over time. If they drop, it may be time to clean up your list again.

Maintaining quality subscriber lists is an important part of avoiding spam filters. High open and click rates signal to ISPs that recipients want to receive your emails.

Follow all email laws and regulations

To avoid being labeled a spammer, it’s crucial to follow anti-spam legislation like the CAN-SPAM Act. Key requirements include:

No misleading content – Subject lines and content must be accurate and match. No bait-and-switch tactics.
Working unsubscribe option – Provide a clear one-click unsubscribe process on all emails. Honor opt-out requests promptly.
Identify your business – Include your company’s physical mailing address and contact info.
Comply with opt-out requests – Removing users from your list when requested is mandatory. Process opt-outs within 10 business days.
Get consent – Only send emails to recipients who have agreed/opted in to receive them. Don’t email purchased lists.

Breaking anti-spam laws can lead to huge fines, blocked IPs, destroyed sender reputation, and inevitable spam folder doom. Follow better email marketing practices instead!

Use double opt-in subscription forms

Speaking of getting consent, double opt-in subscription forms are ideal for building your email lists.

Double opt-in means asking new subscribers to explicitly confirm their email address before adding them to your contact list.

For example, Jane signs up on your website’s newsletter subscription form. She receives an automated confirmation email and has to click a verification link inside. Only after Jane confirms, she is subscribed.

This approach has two benefits:

Prevents fake or mistyped email addresses from signing up and causing bounces.
Ensures subscribers actively grant permission to receive your emails.

Both factors strengthen your sender reputation and minimize spam risk.

Compare that to single opt-in where users are instantly subscribed without any validation. Single opt-in tends to yield lower-quality lists with higher bounce rates. For best results, double opt-in is the way to go.

Improve engagement with better content

Beyond list quality, keeping your existing subscribers engaged also prevents spam filtering issues.

You want recipients to open and click on your emails regularly. This shows ISPs that users want your messages.

Some tips for driving higher engagement include:

Personalize subject lines – Segment your list and tailor subject lines to different interests.
Test different email types – Send a mix of valuable content, promotions, entertaining stories, etc. Monitor engagement across types.
Leverage multimedia – Embed images and videos to make your emails more interactive.
Highlight subscriber benefits – Remind users constantly of the value they get from your emails.
Use visual formatting – Break up text with headers, lists, highlighting, and spacing to improve readability.
Check mobile optimization – Ensure your emails look great on mobile devices where engagement often occurs.

Take the time to test different email approaches and analyze open and click rates. Identify what resonates best with your audience and do more of that!

Warm up new domains gradually

When starting a new brand, don’t immediately blast campaigns to your entire list to avoid triggering spam filters.

Why? Because your domain and IP address are completely unknown to ISPs at first. Spam filters will be cautious and conservative until you establish a sender reputation.

The best practice is to warm up new domains by gradually increasing your email volume over several weeks. For example:

Weeks 1-2: Send 5 emails daily
Weeks 3-4: Increase to 25 emails daily
Weeks 5-6: Ramp up to 50 emails daily
Week 7+: Start sending larger campaign batches

Take things slowly to confirm your domain’s legitimacy with providers before sending thousands of emails. Use this warm-up timeframe to fine-tune your engagement metrics and content as well.

Authenticate your emails properly

Finally, using email authentication protocols like SPF, DKIM, and DMARC adds validation to your messages and helps prevent spoofing/impersonation issues.

SPF confirms the sending server is authorized to send emails from your domain.
DKIM digitally signs messages to verify they have not been manipulated or changed during transit.
DMARC aligns SPF and DKIM to block unauthorized use of your domain.

Setting up proper email authentication takes some technical work but is worthwhile. Consult your email service provider or IT team to configure these protocols.

When all the authentication mechanisms align, your domain reputation improves and the risk of spam filtering decreases. Even individual emails you send direct through an ESP can benefit from using these protections.

Conclusion and Key Takeaways for Avoiding Spam Filters

And there you have it – everything you need to know to dodge spam filters and deliver your email campaigns successfully. Here are the key takeaways:

Spam filters mark emails as junk based on “red flag” criteria like spammy words, odd phrasing, excessive caps, suspicious links, etc. Stay away from these.
Hundreds of spam trigger words exist, typically involving pressure, exaggeration, money, unnatural language, or sketchy offers. Avoid overusing these terms.
However, context matters. Used responsibly as part of natural writing, certain spam words may be fine. Evaluate carefully.
Proactively check your email content using online spam check tools before sending anything. This allows fixing issues proactively.
Focus on sending great content to engaged, opted-in lists. Nurture your sender reputation and deliverability over time.
Follow all CAN-SPAM regulations so you never come across as a shady spammer ignoring laws.
Warm up new domains gradually, use double opt-in forms, authenticate your emails, and emphasize engagement with every email.

Avoiding obvious spam words is just one piece of the deliverability puzzle. But combining thoughtful email writing with the other tips above will help your campaigns reliably reach inboxes for years to come.

Now let’s wrap things up with some examples of how to thoughtfully incorporate certain spam trigger words in your emails when appropriate.

Safely Using Spam Trigger Words in Context

We just covered a massive list of hundreds of spam words and phrases that put your emails at risk of getting flagged. However, should you avoid these terms altogether?

Not necessarily. As mentioned earlier, context is key. Certain situations exist where you may be able to incorporate spam trigger words appropriately without causing issues.

Let’s look at some examples of thoughtfully using risky language by considering the context.

Examples of using financial terms appropriately

Words related to money, banking, credit, and financial topics often trigger filters. But for some businesses, these terms are unavoidable.

How can a bank, insurance company, or lender refer to their own products and services without using industry terminology? They can’t!

For financial companies, the key is using monetary keywords and phrases accurately, transparently, and infrequently.

For example, a bank email with the subject “Low Home Mortgage Rates Available Now!” would almost certainly get labeled as spam.

But an email from the same bank explaining their competitive rate changes in a factual, non-promotional manner can be just fine:

Subject: Updates to Our Home Mortgage Rates
Body: Hello valued customers,

We wanted to inform you that as of July 1st, 2023 our 15-year and 30-year fixed mortgage rates have decreased to 5.1% APR and 5.6% APR respectively. Our rates remain some of the most competitive in the region.

No action is needed on your part, but please reach out if you have any refinancing questions. We’re happy to discuss your options or get you preapproved for free.

Thank you for trusting us with your mortgage and banking needs!

Regards,
Your Favorite Bank

Though the email contains terms like “mortgage”, “rates”, and “APR”, it avoids sounding overly salesy or promotional. This improves its chances of clearing spam filters.

Examples of urgency words in proper context

Pressure-inducing urgency words are another filter minefield. While usually best to avoid, exceptions exist if used wisely.

For instance, suppose a software company is releasing a significant new update that fixes a major bug affecting users. In this case, it would be appropriate to encourage customers to update as soon as possible.

Subject: Important Update – Please Download Today
Body: Hello users,

We recently discovered a critical bug in Version 2.0 of our app affecting the sync feature. This bug may result in lost data under certain conditions.

Our engineering team has issued a patch to fix the problem. Please update to Version 2.0.1 at your earliest convenience to ensure the reliability and security of your data.

You can download the latest version here:
[Download link]

We know many of rely on our app, so we strongly recommend updating before continuing to use Version 2.0 which contains this severe bug. Let us know if you have any issues!

Regards,
The Software Company

While terms like “important”, “download today”, and “at your earliest convenience” add urgency, it makes sense given the context of a critical app update. This would likely pass spam filters.

When hype words may be acceptable to use

Even exaggerations aren’t entirely off limits if applied judiciously. Think like a respectable salesperson pitching an amazing product without going overboard.

For example, language describing a hot new item in an online store’s inventory could work:

Subject: Just In: The Absolute Best Luxury Watch Ever Made
Body: Watch lovers, great news! We just added the Chronomaster Sport ‘Q’ dive watch to our inventory. This may very well be the highest quality and most technologically impressive luxury watch on the planet.

Key features:

Super-durable scratch-proof titanium case
Ultra-precise chronometer-certified movement
Beautiful intricate craftsmanship
Extreme 500 meter water resistance

As you can imagine, this incredible modern masterpiece carries a premium price tag. However, discerning watch collectors like you appreciate true excellence.

Don’t miss your chance to own the ultimate achievement in watchmaking – visit our site to reserve yours today! Once our limited inventory sells out, they will be gone for good.

Thanks for your time,
The Online Watch Store

Even with descriptors like “the absolute best ever”, “highest quality”, and “masterpiece”, the email plays up the product without making unbelievable claims. Likewise, subtly highlighting limited quantity doesn’t feel excessively pressure-inducing.

In the right situation, you can incorporate some hype and urgency carefully without necessarily triggering filters. Just don’t get carried away with it! Keeping language mostly natural and honest is always the way to go.

So in closing, be mindful that context matters when evaluating potential spam words in your emails. Sometimes certain terms may be perfectly appropriate for your situation.

Conclusion and Key Takeaways for Avoiding Spam Filters

Throughout this comprehensive guide, we covered everything you need to know about spam filters and trigger words. To wrap up, let’s recap the key points:

Recap of most problematic spam trigger words

Hundreds of known spam trigger words exist that could flag your emails as junk if overused. The main categories are:

Urgency words – Act now, instant, apply immediately, etc.
Hype/exaggeration words – Risk-free, guaranteed, highest paying, cancel anytime, etc.
Financial words – Earn money, credit score, mortgage, unsecured debt, etc.
Jargon/odd wording – As per, compliance, multi-level marketing, kindly, etc.
Shady product terms – Weight loss, casino, singles, enhancement, etc.

See the comprehensive list above for all 550+ problematic terms we suggest avoiding when possible.

Importance of monitoring context and deliverability

However, language is nuanced. Certain spam trigger words may be fine depending on context. For example:

Financial companies can use industry terminology if done transparently.
Urgency is reasonable for critical app updates and patches.
Some hype fits an enthusiastic product launch announcement.

Evaluate each situation. And remember deliverability depends on more than just word choice – list quality, engagement, authentication, etc. all factor in.

Main tactics for improving email deliverability

Here are pro tips for improving deliverability beyond carefully avoiding spam trigger words:

Actively check for spam words using online tools before sending.
Maintain clean, engaged email lists by monitoring engagement and removing inactive contacts.
Follow all CAN-SPAM regulations to avoid being labeled a spammer.
Use double opt-in forms to build your lists from subscribers who confirmed their interest.
Send awesome content tailored to your audience’s interests to drive higher engagement.
Warm up new domains gradually instead of blasting huge volumes immediately.
Implement SPF, DKIM, and DMARC email authentication to validate your messages.

Avoiding obvious spam words is just one piece of the inbox deliverability puzzle. But combining thoughtful writing with these other tips will help your email campaigns cut through the noise for years to come.

The spam filter gatekeepers are tough, but with the right knowledge you can pass through unscathed. Just remember to write naturally, emphasize value for subscribers, authenticate properly, and keep refining based on hard engagement data.

With some care taken to follow spam laws and email best practices, your messages should reliably end up in the right place – your recipients’ inboxes!

Summary: Avoiding Spam Filters and Trigger Words

Spam filters play an important role in keeping our inboxes free of unwanted messages. But they aren’t flawless. Legitimate emails sometimes get flagged as spam just for innocent use of particular words and phrases.

Here are the key lessons to help your campaigns stay out of the dreaded spam folder:

Spam filters scan emails for hundreds of “red flag” criteria like spammy words, odd language, caps lock, suspicious links, missing unsubscribe links, etc. Avoid these red flags.
Spam trigger words typically involve creating false urgency, exaggerating claims, referencing money, using unnatural language, or mentioning questionable products/services.
Context matters. Used thoughtfully in moderation, certain spam words may be fine depending on your specific situation. Evaluate carefully.
Proactively check your email content using online spam check tools to identify any red flags before sending. This allows fixing issues.
Maintain high-quality, engaged email lists with only active double opt-in subscribers. Nurture your sender reputation over time.
Follow all CAN-SPAM regulations so you never come across looking like an irresponsible spammer.
Use tools like gradual warmup periods, engagement tracking, and email authentication to keep improving your deliverability.
Combine thoughtful email writing that emphasizes value for subscribers with the strategies above to maximize inbox delivery.

Avoiding obvious spam words is just one important piece of the puzzle. But now you have all the knowledge needed to keep your email campaigns out of the dreaded spam folder!

Frequently Asked Questions

Q: How many spam words can I include before triggering filters?

There’s no magic number, but the general rule is to minimize usage of known spam words and phrases. Using 1-2 very occasionally in context is probably fine. But 5+ instances could signal something fishy. As always, excessive repetition of spammy language is risky.

Q: Do spam filters read every word of my email?

Most spam filters don’t analyze the full content word-for-word. Instead they look for patterns, language characteristics, strange phrases, and other holistic red flags. But some more advanced filters do process text more comprehensively. Ultimately there are no guarantees, so write emails accordingly.

Q: What should I do if my email lands in spam?

First, run the email through a spam tool to identify what might have triggered it. Look for spammy words, ALL CAPS, unusual phrases, excessive repetition, etc. Next, check your list quality and remove any inactive subscribers or bad addresses causing bounces. Going forward, avoid high-risk language and improve engagement. If issues persist, try warming up your IP gradually before sending large volumes.

Q: Is it safe to use spam trigger words if my list is engaged?

High engagement helps, but isn’t a guarantee. Spam words in an otherwise perfectly relevant email could still trigger overzealous filters. Play it safe by minimizing unnecessary usage of known spammy terms. Write as you would to a real person. Prioritize value for the reader rather than sales language.

Q: How often should I clean my email list?

A good rule of thumb is checking for inactive subscribers at least quarterly, if not more frequently. Remove contacts who haven’t opened in 6+ months. Regularly pruning disengaged subscribers ensures your open and click rates reflect a quality list.

Q: What happens if I don’t comply with CAN-SPAM?

You risk heavy fines from the FTC or FCC, blocked IPs and destroyed domain reputation, landing exclusively in spam folders, and having your website shut down in severe cases. Follow all CAN-SPAM email regulations. Don’t give providers a reason to blacklist you.

Q: Is buying email lists safe for spam compliance?

No. Purchased email lists are inherently risky. Not only are these people unlikely to engage, but they did not opt in to receive your emails. Using such unvetted lists frequently associates you with spammers in providers’ eyes. Build your own opt-in subscriber lists instead.

Q: What words should I absolutely avoid in emails?

There are no outright banned words that guarantee spam filtering. But in general, be very cautious about using language related to free money/gifts, miracles, enhancements, excessive urgency (“act now!”), or other common spammy terms. Rely more on providing real value to subscribers.