Use gmail as smtp server

Contributed by Albert Pauw (Work in progress)

TheWebalyst: I got this working by changing the sasl_passwd setting (working version below). It is not clear if Albert's "Work in progress" was working or not, but the sasl_passwd setting did not work for me, and appeared to be incorrect so following these instructions should now work.

Just to be sure, we save a copy:

cd /etc/postfix cp main.cf main.cf.org

Now we edit the file main.cf:

The following lines need to be changed:

mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128

change to

mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 192.168.1.0/24

Obviously you add your internal network, 192.168.1.0 is a good guess (192.168.0.0 is another much used one).

(TheWebalyst: Alternatively, if you want to send from all machines on your network and can't get the above working, comment out the mynetworks value with a '#' and insert "mynetworks_style = subnet" instead.) 

If you don't do this, then your bubba won't accept mail for relaying.

relayhost =

change to

relayhost = [smtp.gmail.com]:587 

Add the following lines:

smtp_tls_CAfile=/etc/ssl/certs/ca-certificates.crt
smtp_use_tls=yes
smtpd_sasl_local_domain = $myhostname
smtp_sasl_tls_security_options = noanonymous
smtpd_sasl_application_name = smtpd

Now create or edit the file sasl_passwd and add the following line with your gmail account data:

smtp.gmail.com   Your_Gmail_address:Your_Gmail_password 

save it and run

postmap sasl_passwd 

to (re)generate the sasl_passwd.db file.

Now restart postfix

/etc/init.d/postfix restart 

Look at /var/log/mail.log

tail -f /var/log/mail.log 

and send an email using your bubba (b3) as smtp server.

Redirecting Email for Bubba and Users

Now your bubba can send mail to the world via gmail (as well as acting as an SMTP relay for your network) you might want mail sent to b3 users to end up elsewhere.

I found two postfix settings useful for this, although I (TheWebalyst) admit some ignorance about the ways you can do this.

Always BCC

You can use "always_bcc" to have certain emails copied to a given email address. I have to admit I'm not sure of the scope of this but found that it revealed messages being sent that I didn't know about (e.g. from horde3 and DenyHosts).

always_bcc = email_address

Redirecting User Email

Perhaps more useful, you can avoid having to read mail on b3 by redirecting mails for individual accounts. This Involves the follosteps:

1) Create a relocation map file: /etc/postfix/relocation which contains one line for each redirected user account as follows:

username   email_address

2) Edit /etc/postfix/main.cf and add the following entry:

relocated_maps = hash:/etc/postfix/relocated

3) Generate the map (failure to do this can stop postfix working!) as follows:

postmap /etc/postfix/relocated

4) Restart postfix:

/etc/init.d/postfix restart

Note: if you edit /etc/postfix/relocated you need to rebuild the map database with "postmap /etc/postfix/relocated".