Go Back > Email Service Provider-specific Forums > FastMail Forum
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read
Stay in touch wirelessly

FastMail Forum All posts relating to FastMail.FM should go here: suggestions, comments, requests for help, complaints, technical issues etc.

Thread Tools
Old 30 Jan 2021, 08:18 AM   #16
Senior Member
Join Date: Jan 2017
Posts: 180
Originally Posted by n5bb View Post
The X-Delivered-to header shows the address used by Fastmail to find the delivery account using the aliases assigned to each account. If a To or Cc header includes your address, it is used to create X-Delivered-to. But if there are is no To or Cc header, the envelope address of the received message is used instead.
My understanding is that X-Delivered-to is simply the original envelope recipient.

The X-Resolved-to header shows the target delivery address assigned when the sieve script is executed.
X-Resolved-to comes from taking the address in X-Delivered-to and iteratively following aliases targets and converting local sub-domains to plus-addressing. This has to be done fairly early so that an account can be indentified for per user features like Bayes.

Years ago FM used to deliver a single version of each email, so headers like X-Delivered-to could not be added if there were multiple local recipients. You had to use the combination ["x-delivered-to","Cc","To"] to maximize the number of correct matches and even then it wasn't fully reliable.

These days emails with multiple recipients are converted into separate instances, and X-Delivered-to is reliable. I just use that for the recipient address.
SideshowBob is offline   Reply With Quote

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 06:56 AM.


Copyright 1998-2013. All Rights Reserved. Privacy Policy