Hello,
I recently migrated from Exchange 2010 to Exchange 2013 in my organization. In the past few days, a few users are receiving the "Delivery delayed" notification when sending E-Mails to certain domains only."Remote Server returned '400 4.4.7 Message delayed".
"This message hasn't been delivered yet. Delivery will continue to be attempted.
The server will keep trying to deliver this message for the next 1 days, 19 hours and 59 minutes. You'll be notified if the message can't be delivered by that time."
Current Setup:
I have a public IP *.*.*.82 pointing to the CAS 2013 for mail.domain.com. Public IP *.*.*.81 is the IP for the outgoing E-Mails and the PTR records is already published for this IP, but haven't published the SPF record yet and I am assuming this could be the reason.
Please advise.
Thanks,
Sathish