Postfix SMTP Error (535): Authentication failed
I was working setting up a new Managed VPS for a client today. The client wanted to host their emails on the server so I was setting up Postfix mailserver. The server was Ubuntu 16.04 with Virtualmin and Nginx.
I installed Roundcube for webmail. But when I try to send a test mail I got Postfix SMTP Error (535): Authentication failed.
After researching for a bit, I've found out that I was missing the missing the symlink from /var/run/saslauthd to /var/spool/postfix/var/run/saslauthd. So I created it with following command.
ln -s /var/run/saslauthd /var/spool/postfix/var/run/saslauthd
That fixed the Postfix SMTP Error (535): Authentication failed. Remember to restart Postfix and saslauthd.
warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory
Is another variation of this error.