ChrisB

Got a sendmail (at a site that I don't look after) that keeps bouncing messages:

553 5.0.0 Header Error

Numerous other servers are happy to accept a message from the same application. Is Sendmail very very fussy about messages meeting SMTP RFC?

Can't even submit a message via a manual Telnet:

220 x.remotedomain.com ESMTP Sendmail 8.12.10/8.12.10;
HELO y.y.y
250 x.remotedomain.com Hello [y.y.y], please to meet you
MAIL FROM:me@mydomain.com
250 2.1.0 Me@mydomain.com... Sender Okay
RCPT TO:user@remotedomain.com
250 2.1.5 user@remotedomain.com
DATA
354 Enter mail, end with a "." on a line by itself
TEST MESSAGE

.
553 5.0.0 Header Error

What's wrong with that?

stevencotton

Could be any one of a lot of reasons. Do you have access to the logs? Has anyone modified the sendmail.cf? I've only seen that error before in relation to the message ID.

ChrisB

No access to the Sendmail end

We've found the problem through a customer who runs a site on one of our public servers. Any attempt to send a message to domain which has this Sendmail box as it's primary MX bounces (messages sent via JMail ASP script, a ActiveX SMTP control in a VB app or manually via Telnet).

The very same formatted message will happily relay via a Merak or IIS v5/v6 server (to name two examples).

I'm happy to blame it on the Sendmail end but I don't want it throwing back in my face with the comment that it's just exactly following the RFC protocol (so whilst other servers work, they are technically incorrect).

Chris.

stevencotton

The fact that the same mails sent through another MX work ok points to the sendmail configuration. There isn't anything you can do without having access to that box, sendmail (as with all MTAs) does a lot of work in the background, and a lot of headers are added/removed in the meantime other than what one sends.

You can't do anything else other than send a bare bones mail via telnet. Have you tried a remote delivery to a local account that way?

ChrisB

Yup, tried the basic commands via Telnet (as per first post) and get the 553 error.

I've asked the people at the other end to look in the logs and send me a sample if required.

Thanks Steven

ChrisB

Update time:

I've been sent some logs from the Sendmail server which includes:

2) From x@xx.co.uk to j.x@yy.co.uk gives rise to header errors (carried out by ruleset=check_eoh in sendmail)

Can I PM you the full log Steven?

stevencotton

Mail it, and the sendmail.cf if poss, scoobynet@cotton.dk

ChrisB

YHM

stevencotton

Let me know what happens