I need a solution
Hi, I have a problem that apparently is related to Symantec (I use symantec endpoint use Version 10.5.2).
I have a user who repeatedly get invalid or delay delivery mails.
The message is as follows:
451 4.4.1 [internal] connection was not attempted: domain is marked down (too many connection failures) 421 4.4.0 [internal] failed to connect: no mail servers for this domain could be reached at this time |
What might be happening?
Thanks!