Yahoo servers are rejecting email from your domain SMTP server. This can be caused by several reasons including the ones below:
- If there are no Message-ID or Date headers in the messages being sent by your program
- If the attachments do not follow the exact structure for that file type, these are also considered suspicious and hence quarantined, just in case they pose any form of threat.
- If the message has 2 subjects the mail can be rejected.
Based on my research, Yahoo commonly does this if there are two Subject: entries in the header.
info@elgg.org
Security issues should be reported to security@elgg.org!
©2014 the Elgg Foundation
Elgg is a registered trademark of Thematic Networks.
Cover image by RaĆ¼l Utrera is used under Creative Commons license.
Icons by Flaticon and FontAwesome.