Dropbox Email-based MFA not sending emails

[tester8348629568]

Hi all. I'm an admin in higher education, and while we are not a Dropbox customer, we occasionally have people use their university addresses for personal accounts.

One user apparently had configured their university M365/Exchange Online mailbox as the destination for email-based MFA code delivery.  (I made a test account and that no longer seems to be an option, so I'm guessing the user is grandfathered in & I won't be able to try replicating their issue)

However, they never receive this email.

Being an admin, I ran a trace through our system (Cisco Secure Email in front of M365/Exchange), and absolutely nothing came through. No trace of an accepted message, and no logs of rejections if I'm searching against wildcarded sender domains of *dropbox* or *amazonses*. (Assuming these are using Amazon SES like other Dropbox emails)

The kicker is that other Dropbox emails currently delivery fine. New account emails, marketing emails, etc all deliver. (Possibly related but maybe not.. Dropbox password resets are *also* being currently marked as SCL=8 and quarantined by Microsoft's high-confidence phish policy that is forced upon customers)

Anyone else able to replicate this issue with non-delivery of email MFA messages for Dropbox accounts?

Thanks!

[Walter]

HI there @tester8348629568 - thanks for bringing this to our attention.

If the issue persists after disabling and re-enabling MFA, may we reach out via email to the email address that's associated with your profile here on our Community, so that we can have a  further look internally?

Thanks!