Sendmail Issue
 

I am running Red Hat Enterprise Linux Edition 4 and have recently installed sendmail on a server which I am also using as a web server. For my description, suppose that my hostname is "myhostname" and my domain is "mydomain.com". My issue is that, although mail succeeds in sending to free hosts (such as gmail), it fails at sending to private/paid email hosts. This is because some private ones send a verification back, which fails, causing the original email to bounce. The email was sending as "root@myhostname.mydomain.com", which is what caused the failure. I added the below to sendmail.mc:

MASQUERADE_AS(`mydomain.com')dnl
FEATURE(`allmasquerade')dnl
FEATURE(`masquerade_envelope')dnl
FEATURE(`always_add_domain')dnl

After running "m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf" and restarting sendmail, the from address is still "root@myhostname.mydomain.com". I then created a generticstable file, etc. (as described at linuxgazette.net/issue58/okopnik2.html), and this caused the below to be in the bounced email:

>>> DATA
<<< 550-Verification failed for <root@mydomain.com>
<<< 550-No Such User Here
<<< 550 Sender verify failed

(That was an improvement from having it be "<root@myhostname.mydomain.com>".) However, the headers (from, reply-to, etc.) still have "root@myhostname.mydomain.com" and the email still bounces.

Any help would be greatly appreciated. Thanks!

For reference, I have recently reinstalled sendmail; however, this did not help.

what application are you using in sending mail? like, are you using php or your running it directly in console?

I know that this will sound like a trite comment, but it isn't intended as such.

If you cannot find an easy solution to your problem, consider giving postfix a go. It will take next to no time to set up, the you will be able to solve this issue in 2secs flat.


Rgds