Tag: Sendmail
Setup sendmail to use Gmail’s SMTP server
by Drew Dahl on Feb.18, 2010, under HowTo, Linux, Mail
Well, I did this on Fedora 12, so I’ll be basing everything off of Fedora packages and yum; however, this should work on any distro.
Things you’ll need: sendmail, sendmail-cf, cyrus-sasl
Might need something more, but if so, I’ve overlooked it…
The first thing we’re going to do is setup our authinfo. Do the following:
cd /etc/mail/auth/
vim client-info
In the client-info file you’ve open in your text editor, insert the following line:
AuthInfo:smtp.gmail.com “U:root” “I:username@gmail.com” “P:password” “M:PLAIN”
AuthInfo:smtp.gmail.com:587 “U:root” “I:username@gmail.com” “P:password” “M:PLAIN”
Now, save it, quit your editor, and run the following in the same directory.
chmod 600 *
cd ../
chmod 700 auth
Now, let’s move on to making our certs. Do the following:
cd /etc/mail/certs/
openssl req -new -x509 -keyout cakey.pem -out cacert.pem -days 3650
openssl req -nodes -new -x509 -keyout sendmail.pem -out sendmail.pem -days 3650
cp /etc/pki/tls/certs/ca-bundle.crt /etc/mail/certs
And finally, let's edit our sendmail.mc. Do the following:
vim sendmail.mc
And, add the following to sendmail.mc:
FEATURE(`authinfo’,`hash /etc/mail/auth/client-info.db’)dnl
define(`SMART_HOST’,`smtp.gmail.com’)dnl
define(`RELAY_MAILER_ARGS’, `TCP $h 587′)
define(`ESMTP_MAILER_ARGS’, `TCP $h 587′)
define(`CERT_DIR’, `/etc/mail/certs’)
define(`confCACERT_PATH’, `CERT_DIR’)
define(`confCACERT’, `CERT_DIR/ca-bundle.crt’)
define(`confCRL’, `CERT_DIR/ca-bundle.crt’)
define(`confSERVER_CERT’, `CERT_DIR/sendmail.pem’)
define(`confSERVER_KEY’, `CERT_DIR/sendmail.pem’)
define(`confCLIENT_CERT’, `CERT_DIR/sendmail.pem’)
define(`confCLIENT_KEY’, `CERT_DIR/sendmail.pem’)
define(`confAUTH_MECHANISMS’, `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN’)
TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN’)
Now run:
/etc/init.d/sendmail restart
I think it's all self explanatory for the most part. Happy mailing 
-=EDIT=-06/02/2010
In the above configuration files, a user reported having issues while copying the above information into their config files. The issue was regarding the quotes around various options. So, if you experience any trouble, please try replacing the quotes. (e.g. delete the ones that are there and add them back within your text editor)
