2FA Verification Emails Not Received – Possible Suppression List Issue Dear Box Support Team, We are experiencing an issue where 2-factor authentication (2FA) verification emails from Box are not being delivered, even though Box indicates that the messages were successfully sent. Below are the details of the situation: Issue description: 2FA verification code emails are not arriving Box shows the messages as “sent” Spam, junk, and quarantine folders have been checked with no results Troubleshooting already performed on our side: All known Box sending domains and subdomains have been added to the allow list in Microsoft 365 (Exchange Online / Defender) A mail flow rule has been created to bypass spam filtering (SCL = -1) for Box-related emails Despite these settings, the messages do not reach Microsoft 365 at all and do not appear in Message Trace