Topic: At what point does/should qmail expand an MX cname?

[mrkiwi]

When I send to one of my recipients (who receives mail fine from everyone else) I get an error. Details are;

I send to dave@foo.com
the MX record for foo.com is a CNAME to foo.dyndns.org
foo.dyndns.org resolves (today) to 1.2.3.4
So ... when i telnet to 1.2.3.4 on port 25 and send mail to dave@foo.com, the mail is received fine.

When i send the mail to my outgoing SME (version 7) server to send to him, my MTA (qmail), at some point, converts dave@foo.com to dave@foo.dyndns.org, which is then rejected by the MTA at 1.2.3.4
I then get the standard mailer-daemon failure notice.
gmail, hotmail and other such servers dont do this conversion, hence they get their mail through fine - i'm not 100% on my RFCs, but i think that qmail is doing things wrong here?

Can anyone suggest where i should be looking?

[JonB]

When i send the mail to my outgoing SME (version 7) server to send to him, my MTA (qmail), at some point, converts dave@foo.com to dave@foo.dyndns.org, which is then rejected by the MTA at 1.2.3.4

That's impossible. qmail cannot/does not convert an email address. It reads the recipient address from the email headers from your mail client. Read the man for qmail-remote.

I would have to suspect that your mail client is auto-completing the foo.dyndns.org email address.

Jon

[CharlieBrady]

When I send to one of my recipients (who receives mail fine from everyone else) I get an error. Details are;

I send to dave@foo.com
the MX record for foo.com is a CNAME to foo.dyndns.org
foo.dyndns.org resolves (today) to 1.2.3.4
So ... when i telnet to 1.2.3.4 on port 25 and send mail to dave@foo.com, the mail is received fine.

When i send the mail to my outgoing SME (version 7) server to send to him, my MTA (qmail), at some point, converts dave@foo.com to dave@foo.dyndns.org, which is then rejected by the MTA at 1.2.3.4
I then get the standard mailer-daemon failure notice.

There is no "standard" mailer-daemon failure notice. There are many notices, each specific to a particular failure condition.

Because you have obfuscated your error report, nobody can check details. Because you haven't quoted bounce messages or log files, nobody can tell you exactly where your problem is originating.

MX records cannot legally be CNAME's. Check the recipient domain's DNS at dnsreport.com.

[mrkiwi]

Thanks both for your help,
CharlieBrady - Your final comment (MX records cannot legally be CNAME's.) was exactly it.

When i said "standard mailer-deamon failure notice" i was meaning qmails final "i give up" 550 error - appologies for the term.

Regards,