How do I set up Sendmail to send messages through the outbound filter?

In this article we describe how you can set up the outbound filter on your Sendmail server in a few steps. Under Sendmail you can use different types of authentication. Depending on which variant you choose, a different procedure is required.

Variante 1: Authentication via IP address

With this method you route all messages from your mail server through our filter cloud.

1

Make sure that the IP address of your mail server has been created as outgoing user in EuropeanMX. For instructions on how to set up an outgoing user, please refer to our FAQ article "How do I set up an outgoing user?".

2

Make sure that the correct limits are set for the outgoing user in EuropeanMX.

3

Open the file /etc/sendmail.mc and add the following lines at the beginning below the line pert(-1)dnl:

define(`RELAY_MAILER_ARGS', `TCP $h 587')dnl
define(`SMART_HOST', `[relay.europeanmx.eu]')dnl

4

Run sendmailconfig to apply the new settings. This command automatically restarts Sendmail.

Variant 2: Authentication via username and password (untested!)

With this method you route all messages from your mail server through our filter cloud.

1

Make sure that an authenticating user has been created as outgoing user in EuropeanMX. For instructions on how to set up an outgoing user, please refer to our FAQ article "How do I set up an outgoing user?".

2

Make sure that the correct limits are set for the outgoing user in EuropeanMX.

3

Go to the path where the files sendmail.mc and sendmail.cf are located (usually under /etc/mail/).

4

Create a backup subfolder (recommended: auth/).

# mkdir auth
# chmod 700 auth

5

Create a file with the authentication information (recommended: auth/client-info).

AuthInfo:relay.europeanmx.eu: "U:USERNAME" "P:PASSWORD"

Replace Username with the user name and Password with the password you previously assigned in EuropeanMX.

6

Generate a database from the file and make both files readable for root only.

# cd auth
# makemap hash client-info < client-info
# chmod 600 client-info*
# cd ..

7

Add the following lines to the sendmail.mc file:

define(`SMART_HOST',`[relay.europeanmx.eu]')dnl
define(`RELAY_MAILER_ARGS', `TCP $h 587')
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo',`hash /etc/mail/auth/client-info')dnl

8

Generate the file sendmail.cf.

# m4 sendmail.mc > sendmail.cf

9

Restart the Sendmail daemon.

# kill -HUP `cat /var/run/sendmail.pid` (old-school) -OR-
# make restart (FreeBSD) -OR-
# /etc/init.d/sendmail reload (debian Linux)