I'm having an issue with a client who usually communicates smoothly with their customers via email. Recently, though, their emails to anyone using a Hotmail address are landing directly in the junk folder, which has already caused them to lose a few contracts. I've checked with some reputation websites and even submitted a ticket to Microsoft, but they assure me everything looks fine on their end with no reputation problems. I'm really stumped on what else to investigate, especially since it's affecting Hotmail users specifically.
4 Answers
Check if there's an email signature or any trailers added to the emails. Sometimes these can trigger spam filters. Try sending a plain text email without any signature as a test to see if it still lands in junk.
Make sure your SPF, DMARC, and DKIM settings are properly configured. You can use various online tools to validate them. These settings are crucial for email authentication and could be the reason your emails are getting flagged.
I did check those settings, and they are all configured correctly with no issues when tested.
Try sending a test email using mail-tester.com. It can help identify any problems with your email setup that might be causing it to get flagged by Hotmail.
Thanks! I'll have them run that test.
Just to clarify, is it the junk folder specifically for Hotmail addresses, or could it be going into a different folder under their Outlook account? Microsoft transitioned Hotmail to Outlook a while back, and sometimes emails get miscategorized.
I’ll check on that. Would they be better off emailing users at outlook.com instead of hotmail.com?

I did confirm their signature was marked as "promotional" and removing it helped somewhat, but it didn’t solve the Hotmail issue.