mx record – Gmail: Receiving Microsoft verification emails

I use Gmail (GSuite) for my email – on a custom domain.
It works flawlessly.

Through months though, when I try to log into my Microsoft/Live account, and it requests a security/verification code, I never receive these emails. That has been going on through more than half a year. Not a single email was ever received.

  • I’m 100% sure it’s not in the spam folder
  • I’m also 100% sure I’ve entered the correct email in Microsoft/Live
  • I also looked under Gmail settings to ensure Microsoft’s domain wasn’t blacklisted
  • Since this has been going on for so long, I’m also sure I’ve been patient 🙂

I have triple-checked my MX records and they’re all good.

Does anyone have any idea what can cause this? From what I know it’s only Microsoft-emails which never arrive in my Gmail environment. Everything else works just fine. I’ve read that other people have similar problems, but I haven’t been able to find a solution.

I’ve done a “security replacement” on the account, but that will not work until in 30 days.