Email it 1/3 working

I’ve set up two accounts in virtualmin, an admin@domain and support@domain

Set up the DKIM, spf, txt, etc records at cloudflare

I can send emails, though at first they were getting sent straight to spam

However, I can’t receive email and get errors when trying to login from an email client. It says the certificate is invalid even though I set up the cert in dovecot and postfix config in virtualmin. And second, authentication always fails, even if I know I have the password right. On too of that, installed roundcube from script installer and it can’t do anything-sending gets smtp error 250, saying I’m unauthenticated. I can send email with the ‘mail’ command though. This is true for both accounts

All else works fine, apache with let’s encrypt ssl and everything

How do I get email working?

I’m using Ubuntu 18.04 on a virtualbox vm. Ports forwarded from host, including 465, 993, 587, 25, 995, 80, 443. UFW on host and guest allow these ports. Host runs Ubuntu 18.04 as well