I have just set up virtualmin (using the automatic install.sh approach) on a fresh VPS (Ubuntu 18.04) and have finished running the Post-Installation Wizard as well as running configuration check.
I added a new virtual server and added a user for email to it. I can receive mail sent from my gmail but can’t seem to send anything from my server email to my gmail.
Whenever I try to send a test email from the server, gmail refuses the mail and I get the following error in my inbox:
<myExternalEmail@gmail.com>: host gmail-smtp-in.l.google.com[184.108.40.206] said: 550-5.7.26 This message does not have authentication information or fails to 550-5.7.26 pass authentication checks. To best protect our users from spam, the 550-5.7.26 message has been blocked. Please visit 550-5.7.26 https://support.google.com/mail/answer/81126#authentication for more 550 5.7.26 information. s71si12012776pfc.287 - gsmtp (in reply to end of DATA command)
What am I doing wrong?