Email deliverability - If you own your own domain name and send email from it you must set this up properly

Email deliverability: SPF, DKIM and DMARC

Email has changed in the last several years, if you send email using your own domain names and you don't want your email to:
  1. Bounce back as undeliverable
  2. Your email deliver to people junk or spam folders
You must properly setup, monitor, and manage 3 things: SPF, DKIM, and DMARC

SPF: How you tell the world who can send email with your domain name
DKIM: Make sure your email server signs email using crypto so that it can't be faked
DMARC: Is a email authentication, policy, and reporting protocol. Basically, lets you see who's trying to send email as your domain so you can make sure you've setup the everything, and people aren't sending spam as you.

Please open a ticket to discuss this and get everything setup properly.