Why does my domain reputation seem to drop immediately after getting a new dedicated IP?

When you switch to a new dedicated IP, it has no prior sending history, meaning it starts with a neutral reputation. ISPs are cautious of unknown IPs and will initially treat emails from them with suspicion, impacting your domain's overall deliverability even if the domain itself has a good history. This is why it often appears that emails from new dedicated IPs land in spam .

What is IP warming and why is it so important during an ESP migration?

IP warming is the process of gradually increasing your email sending volume from a new IP address. This helps build a positive sending history and trust with ISPs. Starting small and increasing volume over time allows ISPs to observe your legitimate sending patterns, which helps establish a good reputation for the new IP and, by extension, your domain. It also helps avoid common issues like emails going to spam .

If I keep my domain, why does its reputation still seem to drop?

Even if you maintain the same sending domain, its reputation can be affected. ISPs consider both IP and domain reputation. While your domain carries its history, the new, unwarmed IP introduces a cautious period. Mailbox providers will scrutinize traffic from this new IP, which can temporarily reduce your emails' inbox placement, leading to a perceived drop in domain reputation.

My open rates have halved, but spam complaint rates are low. What's happening?

This could be due to a few factors. First, ISPs might be throttling your emails from the new IP as part of their initial evaluation, which means emails are being delayed. Second, while not strictly spam, new IPs often don't get the same level of prefetching or prioritized delivery that emails from established IPs receive, potentially skewing open rate metrics. Consistent sending to engaged users during warming should help normalize these rates.

What are the best practices to follow to minimize reputation drops during migration?

During warming, focus on sending to your most engaged subscribers first, as their positive interactions will build trust. Gradually increase your sending volume and expand to less engaged segments over time. Ensure all your email authentication records (SPF, DKIM, DMARC) are correctly configured with your new ESP. Always transfer your unsubscribe and bounce lists to prevent sending to problematic addresses. Consistent, good sending practices are key to warming up your sending effectively.

Why does domain reputation drop when changing ESPs and using a new dedicated IP? - Sender reputation - Email deliverability - Knowledge base

Migrating to a new email service provider (ESP) is often a strategic move to enhance email capabilities, reduce costs, or improve deliverability. However, many businesses encounter a perplexing issue: a sudden drop in domain reputation shortly after the switch, especially when transitioning to a new dedicated IP address. It can feel counterintuitive when you are sending the same high-quality campaigns to the same engaged audience, yet your open rates plummet and emails start landing in spam folders.

This drop is a common, albeit frustrating, part of the process. It is not necessarily an indictment of your email practices, but rather a reflection of how internet service providers (ISPs) and mailbox providers (like

Google and

Microsoft) evaluate new sending infrastructure. Understanding the underlying mechanisms of IP and domain reputation, and the concept of IP warming, is crucial to navigating this challenge effectively.

Understanding initial reputation challenges

When you switch ESPs and move to a new dedicated IP, you are essentially introducing a new sending identity to the world's mailbox providers. Each IP address carries its own reputation, a score based on its past sending behavior. A brand new dedicated IP, by definition, has no sending history, which means it starts with a neutral or even non-existent reputation.

ISPs are inherently cautious of unknown IPs because they could potentially be used by spammers. They do not distinguish between a legitimate business transitioning to a new setup and a malicious actor trying to bypass filters. This initial lack of trust from mailbox providers means that even your legitimate emails may be treated with suspicion, leading to lower inbox placement rates and, consequently, a perceived drop in your domain's performance.

While your domain's reputation (the sending domain used in your 'From' address) does carry some weight from your previous sending history, it is still heavily influenced by the IP address used to send the emails. Think of it this way: your domain is your brand's established identity, but the IP is the vehicle. If you suddenly start driving a brand new, unproven vehicle, even if you are a known, reputable driver, the road authorities (ISPs) will initially monitor you more closely. This interplay between IP and domain reputation is key.

Why your existing domain reputation shifts

Your domain reputation is built over time, based on numerous factors, including bounce rates, spam complaint rates, subscriber engagement, and whether your domain appears on any email blocklist or blacklist. When you switch ESPs, you introduce a new sending environment, which can temporarily disrupt these established signals.

Even if your domain itself has a stellar track record, the new dedicated IP lacks that history. ISPs use sophisticated machine learning algorithms that observe sending patterns from both the IP address and the associated domain. A sudden surge in volume from a new, unfamiliar IP linked to your domain will trigger their cautionary measures. It is not necessarily that your domain reputation has permanently dropped, but rather that the new IP is impacting its deliverability.

This can manifest as emails being throttled, diverted to the spam folder, or experiencing delayed delivery. Although your domain reputation is not erased, its influence is temporarily diminished by the unestablished IP reputation. Mailbox providers, such as

Gmail, for example, often consider both IP and domain reputation in their filtering decisions, meaning a low IP reputation can pull down your overall sender perception.

The critical role of IP warming

The solution to this temporary dip is a process known as IP warming. It involves gradually increasing your email sending volume from the new dedicated IP over a period of weeks or even months. This slow, controlled ramp-up allows ISPs to observe your sending behavior and build a positive reputation for the new IP.

During warming, you should prioritize sending to your most engaged subscribers first. These are recipients who consistently open and click your emails, providing positive engagement signals to ISPs. As the IP gains trust, you can gradually expand your sending to less engaged segments. This strategic approach helps to maintain a healthy reputation and prevents your emails from being flagged as suspicious. For more insights on how to handle warming, consider reviewing a comprehensive guide to IP and domain warming.

Many email marketers get concerned when they see a temporary drop in reputation metrics during the initial phases of IP warming. This is often normal and to be expected. The key is to monitor your deliverability closely, looking beyond raw reputation scores to see if your emails are indeed reaching the inbox. If spam complaint rates remain low and positive engagement is observed, it indicates you are on the right track.

The chart below provides an example of a typical IP warming schedule:

Day	Max sending volume
1-3	5,000 emails
4-7	10,000 emails
8-14	25,000 emails
15-21	50,000 emails
22+	Full volume, monitor closely

Please note this is a general guideline, and your actual warming schedule might vary based on your list quality, engagement levels, and ESP recommendations. It is important to remember that building your sender reputation on a new ESP is a marathon, not a sprint.

Strategies for a smoother transition

Before migration

List hygiene: Clean your subscriber lists thoroughly to remove inactive users, bounces, and known spam trap addresses.
Authentication: Ensure your DNS records (SPF, DKIM, DMARC)) are correctly configured for your new ESP. This is fundamental for establishing trust.
Segmentation: Identify your most engaged subscribers who consistently open and click your emails.

A crucial step that is often overlooked is the proper transfer of your suppression lists, including bounces and unsubscribes. Failing to do so can lead to sending emails to invalid or unwilling recipients on your new platform, which will immediately harm your new IP's and domain's reputation. Make sure these lists are fully synchronized before you begin sending.

Additionally, consider setting up a sub-domain for your marketing emails, separate from your main domain. This can help isolate any potential reputation issues during the warming process, preventing them from impacting your primary domain's reputation. It also allows for more granular control over your sending reputation.

For example, if your main domain is yourcompany.com, you might use m.yourcompany.com or news.yourcompany.com for your email sending. Remember that your existing domain reputation will indeed influence the new sub-domain, but the sub-domain will require its own careful warming process to build a strong, independent sending reputation with the new IP.

Views from the trenches

Best practices

Always transfer suppressions lists, including bounces and unsubscribes, to your new ESP before sending.

Follow a structured IP warming plan, starting with your most engaged subscribers.

Maintain consistent sending volumes and patterns throughout the warmup period.

Monitor all relevant metrics, including open rates, spam complaints, and domain reputation.

Consider incorporating a welcome series during warmup to leverage high engagement.

Common pitfalls

Abruptly switching all sending volume to a new, unwarmed dedicated IP.

Not transferring bounce and unsubscribe lists, leading to higher complaint rates.

Ignoring the temporary dip in reputation during the initial warmup phase.

Sending to unengaged segments too early in the warmup process.

Panicking and changing strategy too frequently during the natural fluctuations of warmup.

Expert tips

Understand that machine learning filters react strongly to changes, leading to initial reputation flux.

Focus on inbox placement metrics rather than just public reputation scores during warmup.

A new IP inherently starts with no reputation, impacting domain metrics initially.

Leverage highly engaged user segments to build positive sending signals early on.

Patience is crucial during the IP and domain warmup process, as it takes time.

Marketer view

Marketer from Email Geeks says they were stuck after changing ESPs and moving to a new dedicated IP, with domain reputation dropping from medium to bad despite consistent campaigns and low spam complaints. Open rates halved, suggesting Gmail was flagging emails as spam.

Feb 20, 2023 - Email Geeks

Expert view

Expert from Email Geeks says a new IP inherently lacks a reputation, which directly impacts your domain's reputation. Slow down your warmup process and focus on sending to highly engaged subscribers to mitigate this initial dip.

Feb 20, 2023 - Email Geeks

Navigating your ESP transition

A temporary drop in domain reputation when changing ESPs and using a new dedicated IP is a common and expected phase. It is not an indication of failure, but rather a natural response from ISPs to a new sending identity. By understanding the dynamics of IP and domain reputation, diligently following an IP warming plan, and maintaining meticulous list hygiene, you can successfully navigate this transition. Remember, patience and consistent, positive sending behavior are your most valuable assets in building and maintaining a strong sender reputation.

While it can be frustrating to see your deliverability metrics fluctuate, staying committed to best practices will ensure your domain's reputation recovers and thrives in its new sending environment. For further support, monitoring your blocklist (or blacklist) status and DNS records can provide vital insights during this period.