Emails being marked as spam by microsoft domains only

Question

Hello.

We are sending emails from a developed platform via sendgrid. There are 7 'from' addresses all sending from the same platform, so the characteristics are the same on all the emails. The sending IP is the same. SPF, DKIM, DMARC all check perfectly on all 7 addresses. 5 of the addresses have a microsoft spam score of 1 and are delivered perfectly to all mail clients, however 2 addresses are given a microsoft spam score of 5 & 8 and reliably go to junk when being sent to all microsoft domains such as outlook.com or hotmail.com

they do not go to junk on any other email client, including our )365 tenant which uses Microsoft advanced threat detection anti-spam/anti-virus.

It seems that hotmail.com & outlook.com use a completely different criteria to assess emails that are junk than the rest of the internet and all other mail providers, including their own for O365. Unfortunately it is very difficult to get support for them.

Id be grateful for any help as this is having significant business impact.

Thanks, Steve

Answer 1

Hi @Steve King ,

It sounds like you're experiencing a frustrating issue with email delivery to Microsoft domains like outlook.com and hotmail.com. Despite having SPF, DKIM, and DMARC set up correctly, two of your 'from' addresses are being flagged with higher spam scores and sent to junk folders.

Given that the technical setup is identical for all addresses, the discrepancy in spam scores for the two problematic addresses might be due to more nuanced factors. Here are a few additional considerations:

Email Content and Frequency: Even subtle differences in the content or frequency of emails sent from these addresses could impact their spam scores. Review the content for any potential triggers, such as certain keywords, phrases, or formatting that might be flagged by Microsoft’s filters.

Recipient Interaction: If recipients of emails from these two addresses have marked them as spam more frequently than emails from the other addresses, this could affect their spam scores. Encourage recipients to mark these emails as “Not Spam” if they find them in their junk folders.

Domain and IP Reputation: While the sending IP is the same, the reputation of the specific email addresses themselves can vary. Tools like Microsoft’s Smart Network Data Services (SNDS) can provide insights into how Microsoft views your sending IP and domain.

I hope these suggestions help you troubleshoot the issue.

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