Running IMail 7.14, my users complained about undelivered mails to one specific domain. The checks showed that the domain has multiple MX entries with different cost, e.g.
maildomain.com. IN MX 10 mailserver.maildomain.com. maildomain.com. IN MX 50 backupserver.provider.com.
"maildomain.com" doesn't have any MX records, so it won't be able to receive mail. I'm guessing you are hiding the domain name (please use "example.com" when doing that, so people know what you mean, and you won't cause issues with an innocent domain).
If you are hiding the domain name, you should first try using the Mail Test at http://www.DNSreport.com . For example, if "backupserver.provider.com" is a CNAME, IMail shouldn't send to it.
The first MX is unavailable (meanwhile, I know the reason). However, the secondary MX is *not* used by IMail. Using Nslookup on the Imail server, the entries are resolved properly.
Note that using nslookup on the IMail server may produce different results than IMail will see. If you make sure to enter the DNS server IP that IMail uses into nslookup, you will usually get the same results. But, if you have an entry in the HOSTS file, that will override the DNS settings.
Just a couple days ago I encountered a similar situation -- IMail wouldn't use the backup MX record, and bounced the mail. It turned out that we had hard-coded the IP address of the mailserver in the HOSTS file (because the domain had a broken MX record before).
-Scott
---
Declude JunkMail: The advanced anti-spam solution for IMail mailservers.
Declude Virus: Catches both viruses and vulnerabilities in E-mail, with no annual licensing fees.
--- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)]
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
