EmailDiscussions.com  

Go Back   EmailDiscussions.com > Discussions about Email Services > Email Help Needed!
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read
Stay in touch wirelessly

Email Help Needed! Having problems with your email service, or with the email software you're using? Post your questions and answers here!

Reply
 
Thread Tools
Old 12 Feb 2022, 02:00 AM   #16
n5bb
Intergalactic Postmaster
 
Join Date: May 2004
Location: Irving, Texas
Posts: 8,773
I’m sure that in this case, the Yahoo delivery server kept a copy of the message and also forwarded a copy to a Gmail address. See the Yahoo premium account setup (forwarding was discontinued from free Yahoo accounts on January 15, 2021, but is still available for premium accounts):
https://help.yahoo.com/kb/SLN29133.html

So one copy of the will remain in the Yahoo user Inbox, while an attempt was made to forward a copy to the Gmail account.
  • If the Gmail server refused to accept the message (which is normally the case with a permanent error), a Yahoo server would send a delivery failure message to the original message sender (From header address).
  • If the Gmail server accepted the message but could not complete delivery for some reason (perhaps an account over quota), a Gmail server might send the delivery failure message to the From address.
Bill
n5bb is offline   Reply With Quote
Old 12 Feb 2022, 02:21 AM   #17
hadaso
The "e" in e-mail
 
Join Date: Oct 2002
Location: Holon, Israel.
Posts: 4,653
Quote:
Originally Posted by n5bb View Post
... a typical email message is forwarded through many different servers. If any of those transfers fails, the failure message is sent to the email address in the “FROM” header.

...
Actually the report about failure of delivery is sent to the address in the Return-path header, which is normally the same as the address in the From header, but not always. AFAIK an SMTP server adds the Return-path header and puts there the "envelope from" address (the one reported by the sender in the SMTP "From" command).
I tested this by sending myself a message with different "From" header and envelope from (using the "Send a copy" function in Fastmail) and the address in the Return-path wasn't the address in the From header but rather my Fastmail userid (surprising and disappointing: I am quite sure that in the past the default identity address was used there, and I never want my userid to appear anywhere but in the login screen).
hadaso is offline   Reply With Quote
Old 12 Feb 2022, 08:50 AM   #18
n5bb
Intergalactic Postmaster
 
Join Date: May 2004
Location: Irving, Texas
Posts: 8,773
Quote:
Originally Posted by hadaso View Post
Actually the report about failure of delivery is sent to the address in the Return-path header, which is normally the same as the address in the From header, but not always. AFAIK an SMTP server adds the Return-path header and puts there the "envelope from" address (the one reported by the sender in the SMTP "From" command).
...
Yes, of course you are correct. The delivery SMTP server (where the message is filed into the addressee mailbox) adds a Return-path header copied from the envelope FROM address. So it's not the header From address, but the envelope FROM which sets the error message destination target.

You can read all about this in section 4.4 (Trace Information) of RFC 5321 at:
https://datatracker.ietf.org/doc/htm...21#section-4.4

When auto forwarding, the system doing the forwarding (Yahoo in the example by the original poster in this thread) adds a Return-path header at the top, then uses that Return-path address as the new envelope FROM during the forwarding SMTP session. The new final forwarded destination server then uses the envelope FROM (which is the same as the Return-path header at the previous step, so comes from the original message originating system) to generate the error message.

This is all far too arcane for regular email users! The bottom line is that in nearly all cases, the From address used when you create an original email message is where any delivery error messages are sent.

Bill
n5bb is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump


All times are GMT +9. The time now is 01:13 AM.

 

Copyright EmailDiscussions.com 1998-2013. All Rights Reserved. Privacy Policy