Linux – Configuring sendmail to forward mail for a specific domain to a specific mail server without using MX records

linuxsendmail

I am new to sendmail and would like to configure sendmail to forward all mail for a specific email address to another internal mail server. I need it to ignore the MX records and only send it to the server I specify but am not sure which files to edit or how to configure the sendmail config. Is it sufficient to add the server to the /etc/hosts and the /etc/mail/local-host-names files?

Thanks in advance.

Best Answer

EDIT: seems like you are talking about mail aliases. Look into /etc/aliases or /etc/mail/aliases. After editing that file, run newaliases

I do not believe that Sendmail has transport map capabilities, at least not that i know of. The feature you are looking for is available in Postfix out of the box. Not sure how much this answer would help you though...

There used to be a package called redhat-switchmail that kind of accomplished that, but I am not sure if it is still available, or if its even compatible with your system.

/etc/mail/local-host-names is just for that... local host names... the domains your sendmail server accepts mail for.

What exactly you want to accomplish with /etc/hosts I am not sure...

Depending on your configuration and version of your Sendmail, you need to edit /etc/mail/sendmail.mc and then "make it" into /etc/mail/sendmail.cf. On older versions, you edit /etc/mail/sendmail.cf, but i do not suggest you touch either one of those files if you do not know what you are doing. They are pretty cryptic, to say the least.

Related Solutions

Sendmail : Mail delivery of same domain to internal or external mail server

For the delivery part of email destined for one of these users you can use the "virtusertable" feature. To redirect the email of only some users to an external address, e.g. for your sample users you could add this to your sendmail.mc file:

FEATURE(virtusertable, `hash -o /etc/mail/virtusertable')

Then in the /etc/mail/virtusertable file use something like this to deliver email for a@abc.com locally, and email for b@abc.com or @c@abc.com* to the remote, hosted server:

a@abc.com localuser

b@abc.com b@hosted.server

c@abc.com somebody@hosted.server

Rebuild the virtusertable.db map by running makemap(1), and Sendmail should be able to handle the delivery part of email ok:

# cd /etc/mail

# makemap hash virtusertable < virtusertable

Controlling which local user is allowed to send email is slightly more involved. You might be able to use "relay_mail_from" and access map entries, but since I haven't actually tried this, I'll let someone else answer with more useful details.

Sendmail to Local Domain Ignoring MX Records – Part 2

What I did to disable local delivery. I'll be using the example.com domain.

Requirements:

example.com A entry pointing to IP address assigned to one of the eth interfaces.
/etc/hosts defining example.com assigned to the very same IP address as above
example.com MX records pointing to Google servers (ASPMX.L.GOOGLE.COM, etc)
default sendmail installation (mine was on Ubuntu)

Steps:

vim /etc/mail/sendmail.mc

at the end:

define(`MAIL_HUB', `example.com.')dnl
define(`LOCAL_RELAY', `example.com.')dnl

and then:

sendmailconfig
service sendmail restart

testing:

echo -e "To: user@example.com\nSubject: Test\nTest\n" | sendmail -bm -t -v
echo -e "To: user\nSubject: Test\nTest\n" | sendmail -bm -t -v

You should see it connecting to the google server and then you should see your mail being delivered to your Google inbox.

Best Answer

Related Solutions

Sendmail : Mail delivery of same domain to internal or external mail server

Sendmail to Local Domain Ignoring MX Records – Part 2

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