Send Asterisk voicemail notifications via Gmail

Here is how you can make asterisk use GMAIL to send voicemails

Tested on Issabel distro on Asterisk 16.6.1

1> Login to your Gmail Account (via browser)

2> Set the "Less secure app access" to "ON".  The fast way is to click on this URL after you have connected to GMAIL  http://www.google.com/settings/security/lesssecureapps

You will probably receive some google alerts that this is been set.

3> Install POSTFIX

yum -y install postfix mailx cyrus-sasl-plain

4> Edit the password file and put in your gmail credentials.  You can use VI or NANO (install instructions for nano below)

/etc/postfix/sasl_passwd

If you aren't familiar with Vi, you can install NANO using the following command

yum install nano

Put in the following information, alter it with your credentials for gmail.  This file is going to be encrypted after a successful test so dont worry about your credentials being stored in clear text, it is only for a few minutes.

smtp.gmail.com    GMailUserName@gmail.com:GMailPassword

5> Now we hash (encrypt) the password file so that it can't be stolen.

postmap hash:/etc/postfix/sasl_passwd

6> Edit the file /etc/postfix/main.cf

Paste in the information below and save

smtp_sasl_auth_enable = yes
relayhost = smtp.gmail.com:587
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_security_level = secure
smtp_tls_mandatory_protocols = TLSv1
smtp_tls_mandatory_ciphers = high
smtp_tls_secure_cert_match = nexthop

7> Reload the mail service

smtp.gmail.com    GMailUserName@gmail.com:GMailPassword

8> Send a test message from the CLI

[root@issabel asterisk]# mail SomeEmailAccount@domain.com
Subject: This is an email test
This is a test.
.

If everything worked correctly, you SHOULD get an email to the email account you used via your Gmail Account

If NO email showed up, you can look at the mail log /var/log/maillog

Sep 2 1:20:45 issabel postfix/pickup[50041]: AAD341428DC: uid=0 from=<root>
Sep 2 1:20:45 issabel postfix/cleanup[50295]: AAD341428DC: message-id=<20191129142045.AAD341428DC@issabel.local>
Sep 2 1:20:45 issabel postfix/qmgr[50042]: AAD341428DC: from=<root@issabel.local>, size=427, nrcpt=1 (queue active)
Sep 2 1:20:45 issabel postfix/smtp[50297]: connect to smtp.gmail.com[2607:f8b0:400d:c0e::6c]:587: Network is unreachable
Sep 2 1:20:47 issabel postfix/smtp[50297]: AAD341428DC: to=<SomeEmailAccount@domain.com>, relay=smtp.gmail.com[209.85.144.109]:587, delay=1.9, delays=0.05/0.04/1/0.74, dsn=2.0.0, status=sent (250 2.0.0 OK  1575037247 o70sm10311267qke.47 - gsmtp)

Sep 2 1:20:47 issabel postfix/qmgr[50042]: AAD341428DC: removed

9> Now delete the original file that contained your clear text password.  

rm /etc/postfix/sasl_passwd

10> Now you can go into the system and add the email addresses to your voicemail accounts.