Hello, since few days we are expecting delivery message problems.
Some of domain senders do not deliver us mesage anymore.
For exemple, i've tried to send a message from gmail to my account host on the zimbra server and it never have been delivered. 3 or 5 days after i recieve an email from gmail who says that the message could not be delivered (but do not says why) and if i ve a look on my zimbra server, i can see that the email is in queue and mark as reported.

I would really apreciate some help. Cheers,