Why would my dedicated IP get blocklisted?

Dedicated IPs can be blocklisted due to poor sending practices, such as sending to old or unengaged lists, not properly warming up a new IP, having high spam complaint rates, or being associated with malicious content. ISPs look for patterns that suggest spam, regardless of whether the IP is shared or dedicated.

How do I check if my dedicated IP is on a blocklist?

You can check if your dedicated IP is blocklisted using online blocklist checkers . For major ISPs like Google and Microsoft, use their respective postmaster tools (Google Postmaster Tools, Microsoft SNDS) which provide detailed insights into your IP's reputation and potential blockages.

What is IP warming and why is it important for dedicated IPs?

IP warming is the process of gradually increasing the volume of emails sent from a new dedicated IP address. This helps ISPs recognize your IP as a legitimate sender and build a positive reputation. It's crucial because new IPs have no sending history, and sending too much too soon can trigger spam filters and lead to blocklisting.

How long does it take to get off a blacklist?

The time it takes to get off a blacklist varies depending on the specific blacklist, the severity of the offense, and how quickly you remediate the underlying issues. Some automated blocklists may delist within hours or days once the problem is fixed, while others might require manual review and can take several days or even weeks. Consistent good sending practices are essential for a swift removal.

Is a dedicated IP always better for deliverability than a shared IP?

While dedicated IPs offer more control over your reputation, they are not inherently better than shared IPs in all cases. Dedicated IPs require diligent management and consistent sending volume to maintain a good reputation. Shared IPs can be good for lower-volume senders, as the provider manages the reputation. For high-volume, consistent senders, a dedicated IP generally offers greater long-term control over deliverability, provided best practices are followed.

Why are my dedicated IPs blocked and how can I fix it? - Troubleshooting - Email deliverability - Knowledge base

Acquiring a dedicated IP address is often seen as a significant step towards better email deliverability and more control over your sending reputation. The expectation is that with a dedicated IP, you'll avoid the issues associated with shared IPs, where one bad sender can impact everyone on the same server. However, it's a common misconception that dedicated IPs are immune to blocklisting. In reality, they can and do get blocked, sometimes even more severely because all sending volume is concentrated on a single IP.

When your dedicated IP ends up on a blocklist (or blacklist), it can severely disrupt your email campaigns and transactional mail, leading to missed opportunities and damaged sender trust. The reasons for such blockages vary, but they almost always point back to sending practices that internet service providers (ISPs) deem problematic. Understanding these root causes is the first step toward diagnosis and resolution.

Restoring your dedicated IP's reputation involves a methodical approach, from identifying why it was listed to implementing long-term strategies to prevent future issues. It requires vigilance and a commitment to best practices in email marketing and operations.

Understanding why your dedicated IP is blocked

Even with a dedicated IP, your deliverability is subject to strict scrutiny by ISPs. Unlike shared IPs where a provider manages the collective reputation, a dedicated IP places the entire responsibility of maintaining a good sending score directly on your shoulders. This means any misstep can lead to your IP being blocklisted, affecting all your outbound email. If your dedicated IP is blocked, it's often due to specific sending patterns that signal spam or suspicious activity.

One of the most frequent culprits is insufficient IP warmup. When you acquire a new dedicated IP, it has no sending history, meaning ISPs view it with suspicion. A sudden surge in email volume can trigger automated defenses. If you've just started sending on a new IP, you must gradually increase your volume, a process known as IP warming. You can learn more about what to do when your IP gets blocklisted during IP warmup. Improper warmup is a leading cause of dedicated IP blocklisting.

Another major factor is the quality of your recipient list. Sending to outdated, unengaged, or purchased lists can lead to high bounce rates, spam complaints, and hits on spam traps. ISPs (Internet Service Providers) actively monitor these metrics. A sudden spike in complaints, even if total volume is low, can signal to email providers that your sending practices are problematic. This directly affects your IP's reputation and can result in it being added to a blocklist. For more information on what happens, read our guide on what happens when your IP gets blocklisted.

Furthermore, if your dedicated IP was recently used by another sender (even if you're the first for a new domain), its previous history could impact you. Email authentication failures (SPF, DKIM, DMARC) or sending malicious content like phishing emails can also swiftly land your IP on a blocklist. ISPs are constantly evolving their filtering mechanisms to protect users, and any activity deemed suspicious will be flagged.

Diagnosing the problem

The first step to fixing a blocked dedicated IP is to confirm the blockage and understand its scope. You can start by using a blocklist checker to see which public blacklists (or blocklists) your IP is listed on. Common ones include Spamhaus, SpamCop, and PBL. However, remember that many ISPs use their own internal blocklists that aren't publicly visible.

For major ISPs like

Microsoft (Hotmail, Outlook, Live) and

Google (Gmail), leveraging their respective postmaster tools is crucial.

Microsoft's SNDS (Smart Network Data Services) and

GooglePostmaster Tools provide detailed insights into your IP's reputation, spam complaint rates, and sending volume. Always check these platforms first. For Hotmailblocking your dedicated IP, this is especially important.

Using SNDS to diagnose IP block issues

SNDS provides critical data that can help you understand why your dedicated IP is blocked. Key metrics to review include:

IP status: See if your IP is marked as blocked or has a low reputation. This is usually color-coded.
Complaint rates: A high complaint rate is a major red flag, indicating recipients don't want your emails. Compare this to your internal metrics.
Sending volume: Check if the volume of email detected by Microsoft aligns with what you're actually sending to their domains. Discrepancies can suggest issues like compromised accounts or misconfigured sending setups.
Spam trap hits: If you're hitting spam traps, it means you're sending to invalid or old addresses, which severely damages your reputation.

If you find your IP on a blocklist, you'll need to gather evidence of the problem, such as blocklist listings, bounce messages, and any relevant data from postmaster tools. This information will be crucial when you approach ISPs or blocklist operators for removal. It's important to provide a clear explanation of what caused the issue and what steps you've taken to fix it. Without this initial diagnosis, any attempts to resolve the issue will likely be ineffective.

Strategies for recovery and prevention

Once you've identified the reasons for your dedicated IP's blocklist status, the next phase is to implement corrective measures. This typically starts with thoroughly cleaning your email list. Remove all inactive, bounced, and unengaged subscribers. If you've been using a single opt-in process, consider switching to double opt-in to ensure higher quality and more engaged subscribers. This simple step can drastically reduce spam complaints and improve your overall sender reputation.

Common pitfalls

Many senders face blocklist issues due to these common mistakes:

Poor list hygiene: Sending to unengaged or old contacts, leading to high bounces and spam trap hits.
Volume spikes: Sending large volumes from a new or cold IP without proper warming.
High complaint rates: Ignoring recipient feedback loops or high unsubscribe rates.
Lack of authentication: Missing or misconfigured SPF, DKIM, or DMARC records.

Recommended practices

Adopting these strategies can help maintain a healthy dedicated IP reputation:

List hygiene: Regularly clean your lists, remove inactive subscribers, and use double opt-in.
IP warmup: Follow a strict warmup schedule for new IPs, increasing volume slowly over weeks.
Monitor feedback loops: Pay attention to Google and other ISP feedback loops to address complaints quickly.
Robust authentication: Ensure your DMARC, SPF, and DKIM records are correctly configured and aligned.

Throttling your email sends, especially to specific ISPs that are blocking you, is a good short-term strategy. Rather than sending all 20,000 emails in one go, spread them out throughout the day or even over several days. This signals to ISPs that you are a legitimate sender with a controlled sending pattern. Also, carefully review your email content. Avoid excessive use of spammy keywords, suspicious links, or disproportionate image-to-text ratios, which can trigger spam filters.

Once you've addressed the underlying issues, you can submit delisting requests to the relevant blocklists. Each blocklist has its own process, so check their websites for specific instructions. Be prepared to explain the steps you've taken to remediate the problem. Persistence is key, as delisting can sometimes take time. For example, understanding what Spamhaus blocking your domain means for your IP is an important part of this process.

Maintaining a healthy dedicated IP reputation

Recovering from a blocklist is only half the battle, maintaining a clean dedicated IP reputation is an ongoing effort. Consistent monitoring of your sending metrics, complaint rates, and bounces is essential. Use blocklist monitoring services to get immediate alerts if your IP gets listed again. Also, regularly check your DMARC reports for insights into authentication failures and potential spoofing attempts.

Beyond technical checks, focus on engaging your audience with relevant and valuable content. Segment your lists to ensure you're sending the right message to the right people. This reduces the likelihood of complaints and increases positive engagement, which positively impacts your sender reputation. A high level of engagement can act as a buffer against minor reputation dips, helping to keep your dedicated IP deliverability strong.

Finally, regularly review your email authentication protocols. Ensure your SPF, DKIM, and DMARC records are correctly set up and aligned. These protocols are fundamental to proving your legitimacy as a sender. Strong authentication helps ISPs trust your emails, even if there are minor issues elsewhere. Dedicated IPs offer greater control, but with that control comes the responsibility for meticulous management.

Views from the trenches

Best practices

Rigorously warm up new dedicated IPs by starting with low volumes and gradually increasing them over time.

Implement double opt-in for all new subscribers to ensure high-quality, engaged recipient lists.

Regularly monitor your sending reputation using tools like SNDS and Google Postmaster Tools.

Segment your audience and send relevant content to maintain high engagement and low complaint rates.

Authenticate your emails with SPF, DKIM, and DMARC to build trust with internet service providers.

Common pitfalls

Sending to old, unengaged, or poorly acquired email lists, which can trigger spam traps and complaints.

Sudden, large spikes in email volume without proper IP warmup, causing ISPs to flag your IP as suspicious.

Ignoring bounce rates and spam complaint feedback loops, preventing you from addressing issues quickly.

Failing to authenticate your email properly, making it harder for ISPs to verify your identity.

Using dedicated IPs for multiple domains or varied content types without careful segmentation or separate IP pools.

Expert tips

Throttling sends can be a critical strategy, especially when recovering from a block or dealing with sensitive ISPs.

Consider advanced certifications or partnerships that can help bypass strict filtering by major email providers.

For clients in industries with historically poor data practices, it's wise to start with a minimal number of IPs and scale very cautiously.

Actively engage with your most active recipients first when re-establishing reputation, and only gradually reintroduce less active segments.

Investigate if your IP's neighborhood (surrounding IPs in the same range) has poor senders, as this can indirectly affect your reputation.

Marketer view

Marketer from Email Geeks says a compromised account or highly irregular sending patterns can lead to dedicated IP blocklisting.

2023-01-15 - Email Geeks

Marketer view

Marketer from Email Geeks says launching new campaigns with high volume without proper IP warming can swiftly lead to blocks.

2023-02-20 - Email Geeks

The path to better deliverability

Dealing with a blocked dedicated IP can be frustrating, but it's a solvable problem. The key is to shift from reactive firefighting to proactive reputation management. By understanding the common causes of blocklisting, diligently monitoring your sending metrics, and committing to best practices in list hygiene and email authentication, you can significantly reduce the risk of your dedicated IP being blacklisted.

Remember, a dedicated IP is a powerful asset, but its effectiveness hinges entirely on your sending behavior. Consistent, responsible sending builds trust with ISPs and ensures your emails reach their intended recipients, safeguarding your deliverability and business communication.