Using Gmail as a Sendmail Relay

The revenge this time its personal!

K I just setup sendmail to relay using gmail again,  thought I better post what I have done as my original now out of date post is still getting quite a lot of views.

This is based on my Ubuntu 8.10 Server ( 2.6.27-11-server) all patched up todays date and then I did the below.

First off make sure you can actually resolve gmail.com, working ? good.

sudo apt-get install sendmail
sudo cp /etc/mail/sendmail.mc /etc/mail/sendmail.mc.orig
sudo vi /etc/mail/sendmail.mc

Add the following to the bottom of your virgin sendmail.mc (shift+g to get to end of file):

define(`SMART_HOST',`smtp.gmail.com')dnl
define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
FEATURE(`authinfo',`hash /etc/mail/auth/client-info')dnl
define(`CERT_DIR', `MAIL_SETTINGS_DIR`'certs')
define(`confCACERT_PATH', `CERT_DIR')
define(`confCACERT', `CERT_DIR/CAcert.pem')
define(`confSERVER_CERT', `CERT_DIR/mycert.pem')
define(`confSERVER_KEY', `CERT_DIR/mykey.pem')
define(`confCLIENT_CERT', `CERT_DIR/mycert.pem')
define(`confCLIENT_KEY', `CERT_DIR/mykey.pem')

Save the file.

sudo mkdir /etc/mail/auth
sudo vi /etc/mail/auth/client-info

Add the following line to the new client-info file replacing the text between the greater than and less than signs (did I need to spell that out ?):

AuthInfo:smtp.gmail.com "U:root" "I:<YOUR GMAIL USERNAME HERE>@gmail.com" "P:<YOU GMAIL PASSWORD HERE>"

Save the file.

makemap hash client-info < client-info
chmod 700 /etc/mail/auth
chmod 600 /etc/mail/auth/*
mkdir /etc/mail/certs
cd /etc/mail/certs
openssl dsaparam 1024 -out dsa1024 -out dsa1024.pem
openssl req -x509 -nodes -days 3650 -newkey dsa:dsa1024.pem -out /etc/mail/certs/mycert.pem -keyout /etc/mail/certs/mykey.pem
ln -s /etc/mail/certs/mycert.pem /etc/mail/certs/CAcert.pem
openssl req -x509 -new -days 3650 -key /etc/mail/certs/mykey.pem -out /etc/mail/certs/mycert.pem
chmod 700 /etc/mail/certs
chmod 600 /etc/mail/certs/*
cd /etc/mail
make
/etc/init.d/sendmail reload

Bish Bosh!