Null sender (RFC5321.MailFrom: <>) allows DMARC bypass

Problem reported by Steve Norton - 3/25/2021 at 3:47 AM

Submitted

This is being used by spammers to bypass DMARC.

Maybe related to;

Build 7642 (Dec 3, 2020)

Fixed: Password reset emails might be rejected by some DMARC policies because of blank Return-Path field.

Steve Norton Replied

1/23/2022 at 3:48 AM

This is still an issue in 8048.
I've tested this against a Gmail address and they correctly block the email due to the DMARC policy of the 'From' domain even with a null sender.

Build 7642 (Dec 3, 2020)

1 Reply

Reply to Thread

Related Knowledge Base Articles

Build 7642 (Dec 3, 2020)

1 Reply

Reply to Thread

Tags

Related Knowledge Base Articles