Even when overall deliverability metrics appear similar, a new ESP might underperform compared to an older one due to a confluence of factors. These include weaker sender reputation stemming from new or 'burned' IP addresses and the lack of established sending history, and the absence of existing feedback loops with mailbox providers. A rushed or inadequate warmup process, poorer list hygiene practices, and a less robust or optimized infrastructure in the new ESP can also contribute. Changes in template rendering or link tracking can negatively affect engagement. Different sending limits and the level of adherence to authentication standards (SPF, DKIM, DMARC) between ESPs may further exacerbate the issue. Analyzing metrics by domain, monitoring IP reputation, utilizing tools for reputation analysis and sending consistency are important mitigation steps.
9 marketer opinions
Despite similar deliverability metrics, a new ESP may perform worse than an old one due to factors such as weaker sender reputation, inadequate warmup processes, poor list hygiene practices, lack of established feedback loops, less robust infrastructure, or changes in email rendering. Monitoring domain-specific metrics, IP reputation, and utilizing tools for reputation analysis are crucial. The quality of the IP address, sending volume, template rendering and adherence to email authentication standards all have an affect on engagement.
Marketer view
Email marketer from Sparkpost shares that the new ESP might have changes in template rendering or link tracking, which can affect user engagement. If emails look different or links are broken, users may be less likely to open or click.
12 Jul 2022 - Sparkpost
Marketer view
Email marketer from Email Geeks asks if the postmaster tools have the same grade for the former IPs and new IPs, noting Gmail as a good indicator.
8 Jan 2023 - Email Geeks
3 expert opinions
A new ESP may perform worse than an old ESP despite similar deliverability metrics due to several factors. These include potentially different suppression criteria, overall platform-level reputation differences, and issues with the IP address itself, such as it being new with no history or 'burned' due to previous misuse. Additionally, a new ESP's lack of sending history and the need for a new warmup process can contribute to lower initial results. Volume and sending consistency are crucial aspects that require monitoring.
Expert view
Expert from Word to the Wise explains that the problem may well be the IP address, the age of the IP address, whether it has been used for mail previously, and if so, what sort of mail. New ESPs often allocate fresh IPs that have no history, so you are starting from scratch - you have to build a reputation. But they also often allocate IPs that are relatively cheap, because they’ve been burned by others. If you get a burned IP you are starting out in a hole. Check the IP address reputation on a service like Talos, or Spamhaus.
14 Jun 2024 - Word to the Wise
Expert view
Expert from Email Geeks shares that it's common for an old ESP to get higher clicks/signups than a new ESP, even without a firm explanation. Theories include different suppression criteria or platform-level reputation.
4 Sep 2022 - Email Geeks
4 technical articles
Even with similar overall deliverability metrics, a new ESP can perform worse due to several factors highlighted in documentation. IP reputation significantly affects delivery to Gmail users. Sender health, assessed via complaint rates and spam trap hits, can be negatively impacted by a switch to a new ESP. Strict adherence to email authentication standards (SPF, DKIM, DMARC) is vital, and misconfigurations can lead to filtering or penalties. Different sending limits and throttles between ESPs can also affect engagement rates by causing delays.
Technical article
Documentation from Microsoft SNDS explains that sender health is evaluated by looking at complaint rates, spam trap hits, and other factors. A sudden increase in complaints or spam trap hits after switching ESPs can damage sender reputation, even if basic deliverability metrics look acceptable.
17 Oct 2022 - Microsoft
Technical article
Documentation from AWS SES explains that sending limits and throttles can differ between ESPs. The new ESP might be imposing stricter limits, leading to delays in sending and affecting the timing of emails, which can impact engagement rates.
14 Jul 2021 - Amazon Web Services
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