■■■■■ VPS Server Information ■■■■■
I created a fresh Ubuntu 16.04/Virtualmin VPS which hosts both email and websites at '[login to view URL]'. I use Cloudflare for all of my domains including my VPS domain '[login to view URL]'. I have added MX ([login to view URL]), A , SPF, DKIM and DMARC TXT records for my domains which seem to be valid. All of my domains have Cloudflare SSL certificates, I have installed Cloudflare origin certificates. I have created a second virtualmin virtualserver '[login to view URL]' and added 2 test email addresses 'admin@[login to view URL]', 'info@[login to view URL]'. My server host rDNS is set to '[login to view URL]'. I have added a 'mail' virtual server alias to my '[login to view URL]' virtualmin virtual server.
■■■■■ Issue 1 - Can't receive email ■■■■■
I can't receive external emails to my VPS, I can send email locally from 'admin@[login to view URL]' to 'info@[login to view URL]' but not the other way around. I receive a "Diagnostic-Code: X-Postfix; unknown user" error on my external email account when attempting to send mail to my VPS. It is likely to be something todo with the hostname fields in Postfix.
■■■■■ Issue 2 - Spam ■■■■■
I can send emails successfully from my test email addresses using Roundcube, but they goto recipients spam folders. I have a 'SpamAssassin -1.274 RDNS_NONE' error from [login to view URL] and [login to view URL] produces a few other errors. My SPF, DKIM and DMARC records seem to be valid. I want to ensure emails for any domain I add to virtualmin go to a recipients inbox.
■■■■■ Issue 3 - Email encryption & security ■■■■■
I want to enable Dovecot IMAP/POP3 SSL and Postfix SMTP authentication and encryption for external email clients, and ensure any other configurations are based on best practices for security.