Hotmail, Gmail and Yahoo blocked one of our servers

[Gareth-AWD]

One of our servers can no longer send to Hotmail, Gmail and Yahoo and it came about at the same time.

If I check online databases of spam lists, the server doesn't appear in there. I've submitted the IP to Microsoft who say they Mitigated from their system but the problem still remains.

I've changed the C class IP of the mail send outs and the same thing. It doesn't even go into junk. If I look at the mail queue, Hotmail etc accept the message, it just doesn't appear in the users inbox.

The following are all set:

SPF record and RDNS.

The only thing that works is using PHP Mailer to use another server to send email.

Any advice, pulling my hair out!

 

[Travis]

You might want to check out Mail Queue Manager. It can give you details on why something didn't make it to the intended destination.
WHM > Email > Mail Queue Manager

You might also look at Mail Delivery Reports to check where the failure happens.

 

[Gareth-AWD]

You might want to check out Mail Queue Manager. It can give you details on why something didn't make it to the intended destination.
WHM > Email > Mail Queue Manager

You might also look at Mail Delivery Reports to check where the failure happens.

According to the logs, the mail is delivered. It just never reaches the inbox of the hotmail account.