Postfix relay mark email as spam for hotmail/outlook

Hi

On my mailserver I have a mail-relay with Mailjet, because I have had problems with delivering some emails to domains that use the microsoft spam filter including outlook and hotmail. I have it setup in a way, so only delivery to some domain use the mail-relay.

Recently I noticed that it don´t work or it work, but the email is delivered to the spam folder. Then my first thought was that it was a problem with Mailjet so i signed up for Postmark, but unfortunately I still have the same problem.

Can anyone give some suggestions on what to do. I have tried almost everything that I can think off, but nothing helps. I followed this guide for setting up the mail-relay.
https://www.nerd-quickies.net/2020/07/10/solve-microsoft-email-block-list-errors-instantly/

 

Thanks for your answers.

The problems I have is that emails go to the spam folder for hotmail and outlook email addresses. The result was the same both when using own ip-address and third party service like Mailjet. I have now removed Mailjet and use only my own ip-address.

I contacted Microsoft and followed the instructions in this thread. I got the following answer:

#Main server
"I do not see anything offhand with IP: (xx.xxx.xxx.xxx) that would be preventing your mail from reaching our customers."
I have answered the emails to Microsoft, but I have not yet been able to send emails to the inbox from this ip.

#secondary server
"We have implemented mitigation for your IP (xx.xxx.xxx.xxx) and this process may take 24 - 48 hours to replicate completely throughout our system." After 1 day the emails to outlook/hotmail from this server was delivered to the inbox.

I have tested to send emails with mail-tester.com to make sure that the dns is setup correctly. I have also used Glockapps to see which emails that are delivered to the spam folder. With my main mail server all emails to hotmail/outlook go to the spam folder, but with my secondary server the emails go to the inbox.

Now my question is how to get the main mailserver to not mark the email as spam. Should I try to contact Microsoft again or change ip for the server?

 

Okay

I will double check that my dns-settings are correct and contact Microsoft again. Hopefully it will work this time.

 

Thank you for the help. The problem is now resolved.

It seems like the problem was related to ipv6. I had forgot to add the AAAA record for the mail-server and after I added it, it started working. Now when I sent a mail to outlook and hotmail it was delivered to the inbox for both of my emails-servers.