How To Integrate SendGrid With Postfix
Step : 1
Edit the file /etc/postfix/main.cf
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_sasl_tls_security_options = noanonymous
smtp_tls_security_level = encrypt
header_size_limit = 4096000
relayhost = [smtp.sendgrid.net]:587
Save and close the file.
Step : 2
Edit the file /etc/postfix/sasl_passwd
[smtp.sendgrid.net]:587 yourSendGridUsername:yourSendGridPassword
Add your sendgrid user name and password, you can use your API key.
Step : 3
Make sure the file has restricted read and write access only for root, and use the postmap command to update Postfix’s hashtables to use this new file:
sudo chmod 600 /etc/postfix/sasl_passwd
sudo postmap /etc/postfix/sasl_passwd
Step : 4
Finally restart the postfix
sudo systemctl restart postfix
sudo systemctl status postfix