Postfix and SendGrid Configuration Server-Side on CentOS/RHEL/Ubuntu

SMTP (Simple Mail Transfer Protocol) is a easy way to send email from one server to another. SendGrid provides an SMTP service that allows you to deliver your email via our server instead of your client or server.

Sendgrid Configuration

See Also:

Install Required Packages:

First we need to install postfix packages. You mention command you install the required packages as per your OS flavor.

For RHEL/CentOS 6/7

# yum install cyrus-sasl-plain postfix

For Ubuntu 16.04/18.04

# apt-get install libsasl2-modules postfix


Edit or create /etc/postfix/sasl_passwd file and add the SendGrid information in the file.

# vim /etc/postfix/sasl_passwd 
[]:587 yourSendGridUsername:yourSendGridPassword

Run the following command to restrict read and write from users and update Postfix hashtable using postmap command.

# chmod 600 /etc/postfix/sasl_passwd
# postmap /etc/postfix/sasl_passwd

Postfix Configuration:

Now do the postfix configuration to use SendGrid as our smart host.

# vim /etc/postfix/
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_security_level = encrypt
header_size_limit = 4096000
relayhost = []:587

Restart Postfix

Now restart the Postfix service using following commands.
For RHEL/CentOS 7 & Ubuntu 18.04

# systemctl start postfix
# systemctl enable postfix

For RHEL/CentOS 6 & Ubuntu 16.04

# service postfix start
# chkconfig postfix off

Test Postfix Configuration:

Test the changes by using the following mail command.

#echo "SendGrid and Postfix Configuration" | mail -s "Mail Subject"


SendGrid Official Website

Enjoy it!

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