SMTP Mail tries to route to A record instead of MX

We've seen this at a couple of clients recently running Domino 8.0.x. A user sends an email to a known, valid email address and it gets rejected. The user receives a Delivery Failure Report with a generic “SMTP Permanent Error” message. We get involved and look at the log and notice that the server which the message was sent to was “domain.com”. Looking up the MX records, we find that the MX record should be mail.domain.com or sometimes mail.hostingprovider.com. Domino is using the domain's A record to send mail to for some reason. Evidently the cache used by Domino is incorrect. Stopping and starting the router resolves the issue for the near term, but we have seen this come back periodically.

There's a technote that talks about this issue. The workaround is to create a program document that periodically calls the “tell router update config” command which forces the router to clear the cache and try all pending messages again. We normally will set the program to run once an hour to reduce the possibility of a user reporting an issue. There also may be a hotfix for this if you contact IBM Support. The technote refers to Domino 7, 8 and 8.5 as possible releases where this can occur.

For those that may not know how to create a program doc that calls a server console command:

  • Create a new program document in the Domino directory.
  • On the Basics tab, the Program field should have nserver entered.
  • In the command field, enter -c "tell router update config".
  • Change the schedule to whatever you're comfortable with.
  • Save and close the document.
domino 

See also