How to resolve email deliverability issues with Microsoft (Hotmail/Outlook) in the EU region?

Email marketer from Stack Overflow recommends a slow and consistent IP warm-up strategy, specifically for Microsoft, gradually increasing volume over several weeks to establish a positive sending reputation.

Email marketer from Email Marketing Forum recommends setting up feedback loops (FBLs) with Microsoft to receive information about spam complaints, enabling you to quickly address issues and prevent future deliverability problems.

Email marketer from Email On Acid emphasizes optimizing email content to avoid spam triggers, including using clean HTML, avoiding excessive images, and ensuring a good text-to-image ratio, to improve deliverability to Microsoft inboxes.

Email marketer from NeverBounce says it's important to remove invalid or non-existent email addresses from your sending list. Microsoft will penalize senders that send to old/invalid addresses.

Email marketer from GlockApps recommends regularly checking if your sending IP or domain is blocklisted. Microsoft uses various blocklists so this can help proactively identify deliverability issues and take action to be removed.

Email marketer from Mailjet advises focusing on building and maintaining a strong sender reputation by consistently sending valuable content to engaged subscribers, which is crucial for Microsoft to trust your emails.

Marketer from Email Geeks notes that Microsoft filtering appears more stringent in the EU and suggests pulling all volume and warming again, very slowly.

Marketer from Email Geeks suggests being patient and setting expectations that resolving deliverability issues with Microsoft will take time.

Email marketer from Reddit suggests implementing rigorous list hygiene practices, including removing inactive subscribers and using double opt-in, as Microsoft is particularly sensitive to sending to unengaged or invalid addresses.

Email marketer from Sender highlights the critical role of proper email authentication (SPF, DKIM, DMARC) in establishing trust with Microsoft and ensuring that your emails are not flagged as spam.

Email marketer from SparkPost suggests focusing on improving email engagement metrics (opens, clicks) by sending relevant and personalized content, as Microsoft uses engagement as a key factor in determining inbox placement.

Expert from Email Geeks suggests that with EU accounts, it's good to look at how many recipients are getting mail in a language they don’t normally get mail in.

Expert from Email Geeks shares a few things to look at/consider when experiencing Hotmail deliverability issues: tighten up inactive suppression, review authentication, run a second MSFT warm up, test different content/templates, and review feedback from SNDS and FBL data.

Expert from Spam Resource emphasizes the significance of maintaining a clean IP reputation, particularly with Microsoft, by monitoring SNDS data and promptly addressing any reported issues to avoid being blocked.

Expert from Word to the Wise explains how Microsoft uses engagement filters heavily and senders must focus on earning the engagement of their recipients, and that having low or no engagement could be interpreted as spam signals, especially if combined with other negative indicators.

Expert from Email Geeks explains how they contacted Microsoft support after being unable to sign up for SNDS, providing details on their email practices and engagement rates, which led to Microsoft performing mitigation and restoring normal deliverability.

Documentation from Microsoft explains that the Sender Network Data Services (SNDS) program provides data about your sending IPs, including complaint rates and spam trap hits, which can help identify deliverability problems specific to Microsoft domains.

Documentation from Microsoft outlines best practices for senders, including maintaining clean lists, authenticating email with SPF, DKIM, and DMARC, and monitoring sender reputation via SNDS, helping to improve deliverability across their services.

Documentation from Microsoft explains that the Junk Mail Reporting Program (JMRP) allows you to receive reports from users who mark your emails as junk, providing direct feedback on potential content or targeting issues.

Documentation from RFC Editor details the importance of implementing Sender Policy Framework (SPF) records to authenticate sending sources. This is a requirement for email providers to ensure you are who you say you are and are not sending spam.