How to configure Sendmail to use SMTP AUTH in FreeBSD

This writeup describes how to configure Sendmail to use passwd-based SMTP AUTH under FreeBSD. It was written based on my experiences with FreeBSD 4.7-RELEASE, Sendmail 8.12.6 and Cyrus-SASL 1.5.27. YMMV

Install the Sendmail Source Distribution:

The first step is to make sure the necessary source distributions are installed. You'll need the contrib, lib and usbin source packages. If you've already got those installed, skip ahead and install Cyrus-SASL. Otherwise, follow the steps below:

# su
    (enter your root password)
# /stand/sysinstall

Choose Configure, then Distributions, then src. Select contrib, lib and usbin, then press OK and install the packages.

Install Cyrus-SASL:

Make sure you've updated your ports collection recently, then do this:

# cd /usr/ports/security/cyrus-sasl
# make install clean

From the menu that appears, select pwcheck (and any other authentication methods you want to play around with).

Configure Sendmail:

Edit /usr/local/lib/sasl/Sendmail.conf (create it if it doesn't already exist) and add this line:

pwcheck_method: passwd

Next, edit /etc/make.conf (create it if it doesn't already exist), and add these lines:

SENDMAIL_CFLAGS=-I/usr/local/include/sasl1 -DSASL
    (that's "sasl1" as in "sas-L-one")
SENDMAIL_LDFLAGS=-L/usr/local/lib
SENDMAIL_LDADD=-lsasl

Recompile Sendmail:

# cd /usr/src/lib/libsm
# make cleandir
# make obj
# make

# cd /usr/src/lib/libsmutil
# make cleandir
# make obj
# make

# cd /usr/src/usr.sbin/sendmail
# make cleandir
# make obj
# make
# make install

Edit Sendmail Configuration:

Your Sendmail configuration file is probably /etc/mail/<hostname>.mc, where "<hostname>" is the host name of your computer. If that's not the case, then you can just edit /etc/mail/freebsd.mc. Add the following lines to the file:

dnl SASL Options
TRUST_AUTH_MECH(`GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl
define(`confAUTH_MECHANISMS', `GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN')dnl
define(`confDEF_AUTH_INFO', `/etc/mail/auth-info')dnl

And to put the configuration changes into effect:

# cd /etc/mail
# make
# cp <hostname>.cf sendmail.cf
    (replace <hostname> with the name of your Sendmail config file)

One last command:

# killall -HUP sendmail

And we're done! You should now have a working installation of Sendmail with support for passwd-based SMTP authentication. Enjoy!