Working through something and hoping to get some feedback/different perspectives to look at.
Exchange 2010 one primary domain (@primarydomain.com) with setting to allow incoming from @acceptmailfromotherdomaintoo.com
external filter mxlogic(inbound) only.
suddenly over last several weeks(nothing has changed on servers(exhange or dns) mail from some clients sent to firstname.lastname@example.org isn't making it through. Cleints are gettng 554 check smtp settings, their smpt snippets are showing the a record for the domain rather than mx, which is progogated and can be confirmed on external tools like mxtoolbox.com etc...
1. there was a change from external web person that assigned new ip to @primarydomain.com due to blacklisting issues before.
2. I tested something that when I sent mail to email@example.com from hotmail I got the 554 error, sparadically, I think when I unchecked
"automatically update based on email policy" on a firstname.lastname@example.org user that i added the email@example.com
alias to the mail went through. ??? What could be the relationship/things to look at based on this insight?
3. Both domainprimary and acceptotherdomaintoo are A records with same IP on hosted site.
So, not tha most users can accept email from any of the domains with one set as primary. So for now I have those users that have the issues having their clients use firstname.lastname@example.org.
Thanks really hoping for some activity on this issue and feedback on thinks i can consider but i'm not clear this isnt our issue and not the senders.