We have been having issues with our spam filtering taking a long time sending to our Exchange 2013 environment. We get notifications that they are having problems sending to the server with a message such as:
Apr 1 10:13:46 bolt10b postfix/smtp[20208]: 3fyxmg61Bnz3Sr0f: to=<email>, relay=outlook.domain.com[170.**.**.**]:25, delay=432, delays=57/0/0.47/374, dsn=4.7.0, status=deferred (host outlook.domain.com[170.**.**.**] said: 451 4.7.0 Timeout waiting for client input (in reply to end of DATA command))
Apr 1 10:27:25 bolt10b postfix/smtp[28876]: 3fyxmg61Bnz3Sr0f: to=<email>, relay=outlook.domain.com[170.**.**.**]:25, delay=1251, delays=468/0/0.47/783, dsn=4.4.2, status=deferred (conversation withoutlook.domain.com[170.**.**.**] timed out while sending message body)
So I decided to test telnet command manually while we were getting these messages:
- telnet <server> 25 (externally)
- EHLO test.com
- MAIL FROM: fakeuser@test.com
- RCPT TO: internaluser@domain.com
- DATA
- Blah Blah Blah
- .
But there seems to be a LONG Delay (maybe 20-30 seconds sometimes) between when I hit the period and when I get the response back "Queued mail for delivery"
