~~socialite:icon reddit googleplus stumbleupon twitter~~ =====Configuring gmail as a mail relay with two factor authentication - Ubuntu===== Whilst I was looking through the syslog on my home server on an unrelated matter, I noticed some messages along the lines of: Jan 5 11:36:54 localhost postfix/smtp[29391]: 75858A424AC: SASL authentication failed; server smtp.gmail.com[64.233.184.109] said: 534-5.7.9 Appl ication-specific password required. Learn more at?534 5.7.9 https://support.google.com/mail/?p=InvalidSecondFactor f67sm99639626wmd.13 - gsmtp The key part of the messages being **SASL authentication failed** and **Appl ication-specific password required** . Come to think of it, I hadn't had any emails from the server for a while. In fact, from around about the time I turned on two factor authentication. After some research I managed to piece together what needed to be done to allow two factor authentication for postfix on Ubuntu. In case you haven't to set up gmail as a SMTP relay before, here's the steps to set it up. Configure /etc/postfix/main.cf as follows: # Relaying Postfix SMTP via GMAIL relayhost = [smtp.gmail.com]:587 smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous smtp_tls_CAfile = /etc/postfix/cacert.pem smtp_use_tls = yes Add you gmail credentials to /etc/postfix/sasl_passwd [smtp.gmail.com]:587 MUYSER@gmail.com:MYPASSWD Make sure perms of this file are secure, i.e. r-------- 1 root root 65 Jan 5 11:36 sasl_passwd Compile and hash contents of /etc/postfix/sasl_passwd postmap /etc/postfix/sasl_passwd Restart postfix systemctl restart posfix You'll need to set up gmail to allow less secure apps. The procedure is here: https://support.google.com/accounts/answer/6010255 If you have enabled two factor authentication on your google account, these are the extra steps required: Go to https://security.google.com/settings/security/apppasswords select app > Mail , select device > Other (Custom Name) > create a name > Generate Add the application specific pssword generated to sasl_passwd replacing the one already there: run: postmap /etc/postfix/sasl_passwd restart postfix and you're done. **Still stuck? Maybe we can help.** Contact us [[https://www.upwork.com/o/profiles/users/_~01207a4bc438b48c6e|at Upwork]] Never miss a thing [[http://www.justsomestuff.co.uk/subscribe.php|subscribe to our newsletter]] {{glyphicon>envelope}} or follow us [[http://twitter.com/itsjustsomestuf|on twitter]] {{glyphicon>hand-left}} For more super cool techie stuff [[http://www.justsomestuff.co.uk/theblog|check out our blog!!]] ===Recent Changes=== {{changes>}} ====Contribute to this wiki==== Why not help others by sharing your knowledge? Contribute something to this wiki and [[http://www.justsomestuff.co.uk/hall_of_fame.html|join out hall of fame!]]\\ [[http://www.justsomestuff.co.uk/theblog/contact-page|Contact us]] for a user name and password