The Complete Guide to the Mailspike Blacklist

Oh no! You woke up to find your IP address unfairly trapped on the notorious Mailspike blacklist. Now your emails are bouncing and your inbox deliverability is shot.

How did you end up on this spammer’s death row? And how the heck do you get removed from Mailspike’s blacklist?

This guide will walk you through everything you need to know about Mailspike – how it detects spammers, reasons for blacklisting, getting delisted fast, and avoiding future issues.

Page Contents

What is the Mailspike Blacklist?

The Mailspike blacklist is a well-known email blocklist maintained by AnubisNetworks, the company behind Mailspike cybersecurity services. It aims to identify and block IP addresses sending spam or malicious emails by flagging them as having “bad reputation.”

Understanding how this blacklist works and the criteria it uses can help email senders avoid getting trapped on it inadvertently.

Overview of Mailspike and the Blacklist

Mailspike was founded in 2004 as an IT security company focused on email protection. In 2010, it was acquired by AnubisNetworks and rebranded as Mailspike email security services.

The Mailspike blacklist remains one of its most popular free offerings, used by email service providers worldwide to block potential spam. Let’s look at how it functions.

What does it blacklist?

The Mailspike blacklist targets IP addresses displaying suspiciously high volumes of spamming or malware distribution. Most blacklisted IPs are related to:

  • Compromised computers infected with spam bots/malware
  • Hijacked email accounts used for sending spam/phishing campaigns
  • Servers under the control of professional spammers

Who manages the blacklist?

The Mailspike blacklist is compiled and maintained solely by AnubisNetworks based on data gathered across its proprietary email security network.

It does not accept third-party submissions. AnubisNetworks analyzes billions of emails daily to identify high-risk IPs.

How popular is it?

The Mailspike blacklist is one of the most widely adopted real-time blacklists, with usage by:

  • Over 50% of the world’s largest email service providers
  • Leading cybersecurity solutions like firewalls and antispam filters
  • Thousands of businesses across 150 countries

Its global reach and rapid update frequency make it a formidable force in blocking spam worldwide.

How the Mailspike Blacklist Works

The Mailspike blacklist uses two complementary data sets to detect high-risk IPs:

1. Reputation Data

This tracks long-term behavioral patterns and attributes of IP addresses sending direct emails. The IP’s reputation score is calculated based on:

  • Volume – Abnormal spikes indicate potential spamming
  • Consistency – Sudden large bursts are risky
  • Engagement – Low open/click rates signal ineffective outreach

IPs with very high volume, inconsistent traffic, and poor engagement get flagged as high-risk.

2. Zero-Hour Data

Also called real-time blocklist (RBL), this dataset identifies IPs engaged in active spam campaigns or attacks. Zero-hour listings are based on:

  • Associations – Proximity to other blacklisted IPs
  • Timing – Being part of simultaneous spam bursts
  • Patterns – Similarities in spam content, links, etc.

Zero-hour IPs may be listed and delisted quickly based on updated traffic analysis.

Reputation Data and Scoring

The reputation data compiled by Mailspike uses a statistically weighted score calculated from multiple factors:

  • Volume – Frequency and size of mailings
  • Consistency – Traffic spikes and fluctuations
  • Engagement – Open, click, complaint rates
  • Context – Link/image content, messaging patterns

Additional correlates may also be considered to refine the reputation scoring algorithms.

Based on the aggregate score, an IP is classified into one of several reputation categories:

  • Good – Mostly legitimate traffic
  • Fair – Some risky attributes
  • Poor – Suspicious activity
  • Bad – Strongly indicative of spamming

A poor or bad reputation leads to blacklisting on Mailspike. Good senders may occasionally get mislabeled but can easily request delisting.

Zero-Hour Data Identification

The zero-hour listings focus exclusively on real-time behavior rather than long-term patterns. The criteria used include:

  • Burst timing – Being part of synchronized spam waves
  • Tactics – Using similar evasion tricks and hosting
  • Content – Identical links, images, messaging, etc.

Advanced analytics models profile emerging threats by clustering related attacks. IPs matching the zero-hour threat profile get immediately listed until the attack subsides.

Zero-hour listings are highly transient, lasting from a few hours to a few weeks. They provide dynamic protection against rapidly evolving spam outbreaks.

In short, the Mailspike blacklist catches both long-term abusive senders through reputation data as well as short-term spam attacks via zero-hour listings. Understanding its detection criteria can help you avoid accidental blacklisting.

Are You Blacklisted by Mailspike?

Waking up to find your IP address suddenly blacklisted can ruin your day. But don’t panic yet – it happens even to the most careful senders sometimes.

Let’s go over the usual reasons for blacklisting, how to confirm if you’re affected, and steps to get back to good standing.

Common Reasons for Being Blacklisted

Landing on the Mailspike blacklist typically means something is awry with your email activity. Some common culprits:

Compromised Email Accounts

If your email account gets hacked, cybercriminals can use it to send large volumes of malware or phishing campaigns. The unusual activity would trigger blacklisting.

Tip: Use strong unique passwords and enable two-factor authentication.

Infected Devices on Network

Devices infected with spam bot malware may be secretly sending spam through your network. Servers are especially vulnerable targets.

Tip: Use updated antivirus tools and monitor network activity.

Unauthorized Use of Email Servers

Unpatched mail servers can be exploited by spammers to relay mail anonymously. Even unused servers can get hijacked.

Tip: Plug security holes in mail servers and disable open relays.

Policy Violations by Employees

Staff sending unsolicited emails in bulk for marketing, promotions or other purposes could lead to blacklisting.

Tip: Establish clear email policies and enforce them.

Marketing Emails Marked as Spam

If your marketing messages are viewed as spam by recipients, their complaints will negatively impact your sender reputation. Too many complaints lead to blacklisting.

Tip: Ensure you have opt-in consent, send relevant content, and warm up IP carefully before large mailings.

Shared IP with Other Abusive Senders

On shared hosting plans, the activities of other users on the same IP as you can result in collective blacklisting.

Tip: Use dedicated IPs for important email accounts to insulate yourself.

As you can see, blacklisting often results from factors beyond your direct control. But there are still ways to minimize the risk proactively.

Signs Your IP is Blacklisted

The first indicator of trouble is typically bounce notifications when emails fail to reach recipients with a cryptic block reason.

Some common blacklist-related bounce messages you may encounter:

  • “5.7.1 Access denied. Please see”
  • “550 IP blocked – see”
  • “421 SPM Your IP is listed at blacklist”
  • “451 IP dirty listed in mailspike realtime database”

If you suspect your emails are getting blocked, visit the Mailspike IP check page to confirm blacklisting.

Other secondary signs:

  • Sudden spikes in spam complaints
  • Logs showing blocked connection attempts
  • Inability of certain recipients like Gmail to get your messages
  • Being added to other blacklists like Spamhaus

Don’t ignore the signals. Quickly verify if Mailspike has blackmarked your IP.

Checking if You’re on the Mailspike Blacklist

It’s easy to check your blacklist status on the Mailspike website:

  1. Go to
  2. Enter your full IP address (e.g.
  3. Click “Lookup IP”

If your IP is listed, you’ll see the blacklisting reason mentioned:

  • Z – Zero-hour blacklisted
  • BL – Bad reputation blacklist

You can also request delisting on this page by filling in your contact details and clicking “Request Delist”.

Alternatively, you can also use multi-list blacklist lookup tools like Mystrika which will indicate if your IP is blacklisted by Mailspike along with other lists.

Knowing for sure if Mailspike has flagged your IP can help you proceed to the next step – getting removed from their blacklist so your emails start flowing again.

Getting Removed from the Mailspike Blacklist

Uh oh, Mailspike caught you in its spam trap! While this may feel like a nightmare, delisting is actually a very straightforward process with this blacklist.

Let’s walk through submitting a removal request, how Mailspike processes delistings, and typical turnaround time to be whitelist listed again.

Submitting a Mailspike Delisting Request

If your IP address appears on the Mailspike blacklist, you can easily submit a delisting request through their automated web form.

To request removal:

  1. Go to the Mailspike IP lookup page at
  2. Enter your full IP address and click “Check IP”.
  3. If blacklisted, you will see the “Request Delist” box on the results page.
  4. Fill in your name, company, abuse contact email and hit “Request Delist”.

That’s it! Mailspike’s system will automatically process the request.

Within an hour, you should receive a confirmation email indicating your delisting request was received.

Some tips for smooth sailing:

  • Provide a valid abuse contact email you can access. This is where Mailspike will send updates.
  • Use an official company domain name where possible. It adds legitimacy.
  • Double check the IP address before submitting. A typo could delay results.
  • Keep the request polite and formal. Abuse inbox handlers are people too!

Once submitted, the request goes into Mailspike’s automated delisting workflow. Now let’s look at what happens behind the scenes.

The Mailspike Delisting Process

Mailspike relies entirely on algorithms to process delisting requests. Human analysts do not manually review submissions. Here is what you can expect:

Step 1: Automated Validation

On receipt of delisting request, Mailspike’s system first validates:

  • IP address format is technically valid
  • Email domain has proper MX records setup
  • IP not flagged for abuse by other sources

If checks fail, request is rejected. The email domain is important to confirm you control the IP.

Step 2: Reputation Analysis

For IPs that pass validation, updated reputation analysis is triggered:

  • Recent traffic patterns are evaluated
  • Any new spikes or unusual volumes are flagged
  • Comparision with historical reputation scores

If high risk still indicated, no delisting.

Step 3: Delisting Confirmation

Finally, if reputation returns clean, the IP is removed from the Mailspike blacklist and a confirmation email is sent to the requester.

This automated process enables delistings in as fast as 60 minutes. No human vetting means no delays for edge cases.

Of course, subsequent spammy behavior may lead to re-blacklisting. The system is constantly analyzing traffic.

How Long it Takes to Get Delisted

Most delisting requests are processed within 1 hour by Mailspike’s automated workflow.

You will receive an email confirmation once delisted. Maximum turnaround time is 4-6 hours.

Here are some factors that influence typical delisting time:

  • Blacklist reason – Zero-hour IPs get delisted faster than reputation blacklistings
  • Request accuracy – Correct IP and valid email domain speeds up processing
  • Traffic patterns – IPs with historical red flags undergo more scrutiny
  • Time of submission – Non-business hour requests may take longer

As long as your request passes automated validation and reputation analysis, you can expect to be whitelist listed by Mailspike in under 6 hours.

Relief comes quickly with Mailspike once you submit a proper delisting request. Ensure any major issues like compromised accounts or infected devices are resolved beforehand though, or you risk returning to the blacklist just as fast!

Avoiding Future Blacklisting by Mailspike

Phew, you finally got off Mailspike’s blacklist! But before celebrating, it’s wise to take steps to prevent being blocklisted again.

Here are some tips to identify issues, follow best practices going forward, and use tools like Mystrika to boost your sender reputation.

Identifying and Resolving the Root Cause

Any blacklisting indicates something suspect in your email activity. Before continuing business as usual, invest time to diagnose the reason:

  • Review email logs to check for unusual spikes, traffic sources, or suspicious content patterns
  • Audit staff email practices and watch for policy violations
  • Inspect devices on network for malware and unauthorized access
  • Evaluate if marketing content could be construed as spam by recipients
  • Speak to your email host/ISP to understand causes flagged by Mailspike

Finding and fixing the root problem is key to avoid landing back on the blacklist.

Common actions taken may include:

  • Switching to dedicated IP and implementing firewalls
  • Installing updated antivirus and monitoring software
  • Establishing clear email use policies for employees
  • Warming up IP reputation before major marketing campaigns
  • Refining email content to focus on relevance and personalized messaging

Be proactive with diagnosing and addressing any potential issues before resuming full emailing.

Best Practices for Email Sending

Exercise caution with your sending habits, volumes and content to minimize spam risks:

  • Get opt-in consent – Only email subscribed or purchased lists
  • Honor unsubscribes – Don’t force people to receive emails
  • Send relevant contentAvoid keywords that trigger spam filters
  • Personalize messaging – Use first names, custom content
  • Warm up IP slowly – Gradually increase volumes by 25-50% weekly
  • Monitor engagement – Healthy open and click rates indicate interest
  • Check blacklists regularly – So you can appeal listing before sending campaigns
  • Have a blacklist recovery plan – With pre-verified contacts for sender reputation rebuilding

Following best practices goes a long way in maintaining your sender reputation and avoiding issues that lead to blacklisting.

Using Warmup Services like Mystrika

Specialized IP warmup solutions like Mystrika can help improve deliverability and avoid blacklist triggering:

Gradual Volume Ramp-Up

Mystrika warms up IP addresses by gradually increasing sending volumes to vetted inbox providers. This builds up positive sender reputation.

Clean High-Quality Warmup Pool

Its proprietary pool uses pristine seed IPs and engaged recipients to minimize spam risks during IP warmup.

Dedicated Seed sending

Mystrika uses dedicated seed IPs for customer onboarding which prevents IP blemishes from impacting new users.

Unibox Inbox Management

The Unibox feature provides unified inbox access to monitor engagement across all warmup sending.

Detailed Analytics

In-depth metrics on open, clickthrough and complaint rates help gauge sender reputation progress.

Automatic List Hygiene

Mystrika automatically detects and removes unresponsive or complaint-generating recipients to keep pool deliverability high.

Affordable Plans

Pricing starts at just $15 monthly for 5,000 contacts making it easy for small businesses to employ.

Using a service like Mystrika to methodically warm up and monitor IP reputation is an excellent safeguard against sudden Mailspike blacklisting incidents down the road.

Dodging future issues with Mailspike starts with vigilance – auditing past problems, optimizing sending habits, and protecting sender reputation. A proactive approach can help preserve your hard-won whitelist status for good.

Who Uses the Mailspike Blacklist?

With over 10 billion emails analyzed daily, Mailspike provides extensive visibility into global spamming threats. This makes their blacklist an invaluable resource for major email platforms and cybersecurity tools.

Mailspike Usage Among Email Providers

The Mailspike blacklist helps protect inboxes around the world. It is integrated into email infrastructure by:

  • Microsoft – To block abusive senders from Office 365, Outlook, Hotmail and other Microsoft email services.
  • Google – As a contributing source for Gmail’s spam detection and blocking algorithms.
  • Amazon – To identify high risk IPs sending emails through Amazon SES infrastructure.
  • Oracle – To flag suspicious traffic across Oracle Responsys and Eloqua marketing clouds.
  • Zoho – To prevent spamming IPs from reaching inboxes on the Zoho email platform.

In addition, major email providers like Rackspace, Fastmail, Yandex,, and GMX rely on Mailspike data to maintain inbox quality.

It is one of the most widely adopted real-time blacklists, with a global spam detection network.

Usage in Cybersecurity Solutions

Beyond email platforms, the Mailspike blacklist also fortifies security solutions like:

  • Cisco – Mailspike data integrated into Cisco firewalls and email security appliances to block dangerous IPs.
  • SonicWall – Powers real-time threat detection in SonicWall network security products.
  • Sophos – Used as a supplemental threat feed for identifying spam sources.
  • Barracuda – Leveraged for improving spam and virus detection across Barracuda offerings.
  • Trend Micro – Additional threat intelligence integrated into Trend Micro email and network monitoring tools.
  • IBM – Mailspike lookups included in IBM Security email gateway solutions.

The blacklist is also used by many managed service providers in proprietary network and email defense tools to protect enterprise inboxes.

Why Choose Mailspike?

What makes the Mailspike blacklist so ubiquitous?

  • Speed – Real-time updates every 60 seconds makes it ideal for dynamic security filtering.
  • Precision – Advanced analytics and correlations spot high-risk IPs with low false positives.
  • Ease of use – Simple REST API lookups and global availability simplify integration.

With cutting-edge detection capabilities honed from analyzing billions of emails daily, Mailspike has earned its reputation as a universally trusted blacklist for both email services and cybersecurity developers.

Key Facts About the Mailspike Blacklist

Curious about the scale and inner workings of Mailspike’s blacklist operations? Let’s explore some key statistics that highlight its extensive reach.

Number of IPs Currently Blacklisted

At any given time, the Mailspike blacklist contains approximately 3 million IP addresses flagged for spamming or malware distribution.

This includes:

  • ~2 million IPs blacklisted for bad reputation.
  • ~1 million IPs zero-hour listed as part of active spam campaigns.

On average, over 3,000 new IPs are added daily and a similar number removed as threats evolve.

Mailspike maintains one of the larger and more dynamic blocklists continually updated based on the shifting spam landscape.

Its aim is precision over volume. Advanced reputation scoring avoids penalizing legitimate senders. But IPs confirmed as threats face swift blacklisting.

Most Common Types of Blacklisted IPs

The majority of IPs on the Mailspike blacklist belong to:

  • Spam botnets – Compromised devices infected with malware that causes them to send spam without the owner’s knowledge. These make up over 75% of listed IPs.
  • Hijacked servers – Unsecured mail servers taken over by spammers to route mail through them anonymously. About 15% of IPs.
  • Fake accounts – Large scales of fake accounts created on free email platforms like Gmail, Outlook, and Yahoo primarily for sending spam campaigns. Around 5% of IPs.
  • Script kiddies – Amateur individual spammers typically trying to promote questionable products, services, or sites. Under 3% of IPs.
  • Email spoofer networks – Groups specializing in using technically forged sender identities to bypass antispam filters. About 2% of IPs.

Understanding common blacklist sources can help identify risks needing safeguards.

Frequency of List Updates

The Mailspike blacklist is updated extremely frequently from its global threat intelligence network.

  • Zero-hour dataset – Updated every 60 seconds based on real-time activity monitoring of spam outbreaks and attacks.
  • Reputation dataset – Recalculated every 5 minutes using rolling windows of sender traffic and behavior analytics.
  • Public dataset – Refreshed every 2 hours for blacklist APIs and online lookup access.

This represents one of the most rapid blacklist update cycles, optimized for responding to rapidly evolving email threats.

The continuous analysis and massive data volumes involved allow Mailspike to provide high-accuracy listings with minimal false positives. Speed is balanced with precision.

Knowing its operations scale and velocity provides useful context on Mailspike’s core competence – tracking and curbing spam at its source in real-time.

Key Takeaways

Getting unexpectedly blacklisted by Mailspike can be disruptive, but isn’t the end of the world. Here are the key lessons:

  • Mailspike uses advanced analytics on reputation data and real-time activity to identify IPs sending spam or malware.
  • Typical blacklist reasons include compromised accounts, infected devices, hijacked servers, graymail marketing, and sharing IPs with spammers.
  • Monitor bounce errors and check Mailspike’s site to confirm if your IP is blacklisted.
  • Submit a delisting request through their automated web form and you’ll be removed within hours.
  • Diagnose and resolve the root cause before resuming emailing to avoid reappearing on the blacklist.
  • Warm up IP reputation slowly, follow best practices, and use services like Mystrika to maintain deliverability.
  • Major email providers and cybersecurity tools leverage Mailspike data to protect inboxes.
  • Billions of emails are analyzed daily to update the blacklist every few minutes, blocking emerging threats.

With vigilance and safe email habits, you can manage Mailspike blacklisting risks and focus on legitimately engaging audiences.

Frequently Asked Questions

Let’s review answers to some often asked questions about the Mailspike blacklist.

What is the Mailspike blacklist?

The Mailspike blacklist is an email blocklist maintained by AnubisNetworks to identify IPs sending spam or malware. It uses reputation scoring and real-time threat intelligence to dynamically list high-risk IPs.

How does Mailspike detect spammers?

Mailspike analyzes billions of emails daily across two datasets – reputation data tracking long-term IP behavioral patterns, and zero-hour data identifying IPs engaged in active spam campaigns. Advanced analytics identify IPs exhibiting suspicious characteristics.

Why was my IP address blacklisted by Mailspike?

Typical reasons include compromised email accounts, infected devices sending spam, hijacked email servers, policy violations by staff, or sharing hosting IP with a spammer. Marketing emails marked as spam by recipients can also lead to blacklisting.

How do I check if I’m blacklisted by Mailspike?

Go to, enter your IP address and click “Lookup”. If blacklisted, you will see the reason mentioned as “BL” for reputation blacklist or “Z” for zero-hour listing.

How can I get removed from the Mailspike blacklist?

Submit a delisting request through their automated web form on the lookup page. Provide your contact details and a valid email address. Mailspike will review and remove your IP within 1 hour if your reputation checks out clean.

How long does Mailspike blacklist removal take?

Most delisting requests are processed in under 60 minutes. The automated system validates the IP, reanalyzes reputation, and delists it if no active threats appear. You’ll receive a confirmation email when removed.

How can I avoid being re-blacklisted by Mailspike?

Diagnose and fix the root cause of blacklisting, follow best practices for email sending, warm up IP reputation slowly, and use services like Mystrika to maintain optimal deliverability.