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How do you specify the FQDN (Host and Domain Name) that a mail server presents itself as in HELO/EHLO when sending outgoing email with sendmail?

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3 Answers 3

up vote 8 down vote accepted

I added the following in sendmail.mc:

define(`confDOMAIN_NAME', `mail.foo.com')dnl

and then:

m4 sendmail.mc > sendmail.cf
service sendmail restart

I also verified that this worked with the email verifier service at http://www.port25.com/domainkeys/ (auth-results@verifier.port25.com). Neat service, you send it an email and it replies to the from header with information about your SPF, Domain Keys, etc...

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For completeness - one can also use


if one needs more absolute control (e.g. in a freeb-bsd jail it may be desirable to have the confDOMAIN_NAME and MASQUERADE_AS set very different than the HELO/EHLO names.


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define(confSMTP_LOGIN_MSG',$j; $b')dnl

Also configure /etc/hosts like below

xxx.xxx.xxx.xxx server server.yourdomain.com server server server.yourdomain.com server

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