the problem occurs regularly on our domino servers. We have a domino cluster runing on W2k.
We are using a load balanced smtp gateway for outgoing mails. its MX record name is smtpout, and it contains 3 servers smpt001 to smpt003.
Sometimes outgoing mails starts piling up in the waiting list as the servers seems to not be able to resolve the name smtpout.
We found a workaround putting smtp001 instead of smtpout in the global gatway field. There is no MX record for smtp001…
I am assuming it means that, when domino cannot resolve a MX name, it tries to resolve an host name. am I right ?
Does someone know wether there is any issue concerning MX name resolution, and how to solve the problem?
thx in advance.
Subject: outgoing routing problem and MX records
Hmm, the MX record itself is not used in this scenario. Only the actual DNS hostname resolution for smtpout would provide a valid IP address.
You may have an issue with one DNS server having the host record for smptout, while another does not.
Your best bet would be to use nslookup and query all your DNS servers to see what smptout is resolving to.
Again, the MX record is not what’s being used to resolve the hostname. The MX record simply tells the DNS what host to use for this domain to receive mail at. If it’s your outbound smtp gateway, it wouldn’t be used in this fashion.
HTH, Matt
Subject: RE: outgoing routing problem and MX records
As far as I understand a Domino server is positioned as a MTA (Mail Transport Agent) as sendmail is and as such it should follow RFC#974. In short this means the server should decide where to deliver mail to by resolving first the MX-records and when unavailable resolve the A-records.
In the case of adding an A-record for an hostname, I noticed that the Domino server is not obeying these rules; actually it will only use the A-records, which results in masquerading the MX-records completely. Although multiple IP-addresses can be registered on a hostname, only using A-records will stop the automatic load-balancing & fail-over mechanisms of using MX-records.
By the way the configured smarthost should be fully qualified…