FireEye
FireEye is a spam filter, block list, and firewall solution for businesses. Mail is routed through mailservers owned by FireEye before it's passed along to the recipient domain's mailservers for final delivery. The recipient is able to manage a lot of delivery settings such a allow lists, so it helps to ask the recipient to run the described debugging tests in the user guide to identify and resolve delivery issues.
Codes
- 550↑
550 5.7.26 <example@example.com>: ETP205 DMARC Failure for domain
The message failed the DMARC policy for the sending domain. If the sending domain has a reject policy set for DMARC, the message must pass DKIM or have SPF aligned to the domain with a custom Return-Path. To resolve this, you'll need to contact your email service provider to see how to send a message that passes DMARC support.