Skip to main content
Question

2FA Verification Emails Not Received – Possible Suppression List Issue

  • January 29, 2026
  • 1 reply
  • 27 views

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

 

 

Because the messages never reach our mail system, we suspect the recipient address or domain may be on a suppression list on the Box side.

 

Request:

Could you please check whether emails to our domain are currently suppressed or blocked on Box’s mail delivery system?

If so, we would appreciate it if you could remove the suppression so that 2FA emails can be delivered normally.

 

Recipient domain:

wre-inc.jp

 

If you need the full email address for investigation, please let us know and we will provide it securely.

 

Thank you very much for your assistance.

 

Best regards,

kohdai
WRE INC.

1 reply

Rona Box
  • Community Manager
  • January 29, 2026

Hi ​@kohdai

Welcome to Box Community, and we’re glad to assist. 

I’ve gone ahead and created a support case for your MFA issue. And in a short while, a member from the Box Product Support team will reach out to you, please keep an eye out. 

 

Thanks for posting and we hope to sort this out very soon!