Gmail + Postfix on Ubuntu 14.04

if I tell you that the draft of this article has already existed for 400 days (more than a year)! You may wonder how ridiculous I am to not finish it earlier. Okay, the fact is that I put too much things inside one article. Now, I plan to break it up into a series of articles.

In this article, you will know how to setup a free Gmail Relay on your ubuntu server. There maybe quite a lot of online resources to do the simliar thing, but I prefer to write my own as a example and to refresh my forgetful brain. 😀

Installing Postfix

Install Postfix using the following command:

sudo apt-get install postfix

You will see this prompt at some point. Select Internet Site.

Screenshot from 2016-04-13 22:43:47

Screenshot from 2016-04-16 17:07:18

Postfix Configuration

Once the installation is finished, change your terminal’s current directory to


Configure Gmail account and password

create a file call gmail_passwd, replace the information with your credentials.


execute the following command to generate a postfix database.

sudo postmap /etc/postfix/gmail_passwd

For safely reason, you should allow only the root user can access this 2 files.

sudo chown root:root /etc/postfix/gmail_passwd /etc/postfix/gmail_passwd.db
sudo chmod 0600 /etc/postfix/gmail_passwd /etc/postfix/gmail_passwd.db

 Configure your Relay Server

open /etc/postfix/ with whatever editor you like:

vim /etc/postfix/

add the following line to map your credentials

smtp_sasl_password_maps = hash:/etc/postfix/gmail_passwd

Enable TLS and sasl authiencation for Gmail SMTP Server

smtp_use_tls = yes
smtp_sasl_auth_enable = yes

Gmail SMTP Server does not support postfix’s security options. Reset them by:

smtp_sasl_security_options =

Relayhost field means the SMTP relay host. Please put the GMail SMTP server address here. Make sure this address is identical to the one in gmail_passwd

relayhost = []:587

here is the complete version of the

# See /usr/share/postfix/ for a commented, more complete version

# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# TLS parameters
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_use_tls = yes
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtp_sasl_password_maps = hash:/etc/postfix/gmail_passwd
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = office-local
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = office-local, localhost.localdomain, , localhost
relayhost = []:587
mynetworks = [::ffff:]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

reload the configuration:

service postfix reload 

check the status by:

tail -f /var/log/mail.log

check mail.err if there is any error. This file may not exist if there is no error, or it is the first time of you to configure mail related service.

tail -f /var/log/mail.err

Gmail Account Setting

Screenshot from 2016-04-16 16:34:10

Postfix may not works with the default security level of Gmail. Please turn on the “allow less secure apps” option via this link:


mailx is a popular utility in Linux World for sending and receiving mail in terminal. Execute the following command to install it.

sudo apt-get install mailx

Now you can test your postfix configuration by sending a mail to someone. Replace with a valid email address.

echo "Hello Body" | mail -s "Hello Subject" -a

If it was sent successfully, you should see this in the mail.log:

Apr 16 08:41:57 office-local postfix/smtp[1274]: 1603753E: to=<>,[]:587, delay=1723, delays=1720/0.01/1.4/0.85, dsn=2.0.0, status=sent (250 2.0.0 OK 1460796117 h5sm69972904pat.0 - gsmtp)
Apr 16 08:41:57 office-local postfix/qmgr[1197]: 1603753E: removed

 Trouble Shooting

Apr 16 08:27:23 office-local postfix/smtp[1007]: E81E93C5: to=<>,[]:587, delay=7, delays=0.01/0.01/7/0, dsn=4.7.14, status=deferred (SASL authentication failed; server[] said: 534-5.7.14 < qQtdCND0kjQn0lwMS5NJc9nXMTotKJG76X83IjhjNi5jaGjyZed5WfHf_Rm0SxoaiwFAAU?534-5.7.14 tvpINwFpyp2YOKpYmEnCnlmUn33voaf7jG8lN71043p3bgcKNY8Zqk2WB-zKKEoWW58zkM?534-5.7.14 uwn5lZcHpxEJvx5HXAEf0MQcOu_EVJLEFByoP35IPcKquJM5qnI4nBVGzFD93uC6IaSxDH?534-5.7.14 DhDeKmFa94G2XQXZItNqqLtrW8Yco> Please log in via your web browser and?534-5.7.14 then try again.?534-5.7.14 Learn more at?534 5.7.14 n74sm69735534pfa.45 - gsmtp)

your Gmail account is not allow less-secure apps to sign-in



Configure Postfix to Use Gmail SMTP on Ubuntu


One thought on “Gmail + Postfix on Ubuntu 14.04

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