1815559 - Delivered-To header ignored when selecting reply identity (for catch-all)

Status: RESOLVED FIXED

(Thunderbird :: Account Manager, enhancement)

Description

[Cimbali]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/109.0

Steps to reproduce:

• Setup an account with addresses that accept aliases, i.e. with protonmail [e-mail] (as default server identity) and [e-mail] (as second identity)
• Setup a different (unrelated) account with a catch-all address, e.g. *@cimba.li
• Attempt to reply to an aliased email, i.e. sent to [e-mail]

Actual results:

Selected reply identity is the default identity, [e-mail]

Expected results:

Selected identity should be the receiving identity, [e-mail], matched in the email headers with “Delivered-To: [e-mail]”

• If an email is sent to [e-mail] instead of [e-mail], the correct identity is matched.
• This happens when at least an email address has catch-all enabled, even if it’s completely unrelated (as in a different domain, servers, and all)
• If there is no catch-all at all, then the delivered-to header is checked

It seems delivered-to header was initially used only on replies to lists, and then as a hint for any received email since circa 2012, only dropped in the changeset that introduced catchall (if catch-all is enabled, and still used if catch-all is disabled). RFC 9228 describes “alias processing” (in this case [e-mail] -> [e-mail]) as a valid use of this header.

I think either one of these 2 fixes should be implemented:

• append the last delivered-to address (as returned by findDeliveredToIdentityEmail()) to the list of hints used for matching (collectedHeaderAddresses)
• add “delivered-to” to the default list in mail.compose.catchAllHeaders

These options only differ if there are repeated “delivered-to” headers. I’m not 100% sure of the implications of that -- findDeliveredToIdentityEmail() seems to go to some effort to check latest headers first.

Comment 1

[Cimbali]

Attachment: Bug 1815559 - Expand use of "delivered-to" to find identity to catch-all. r=mkmelin

Adds the “delivered-to” to the list of default headers to use to
identify the identity when catch-all is active. Note that delivered-to
is already used when catch-all is off.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/d9a3a27f769f
Expand use of "delivered-to" to find identity to catch-all. r=mkmelin

Comment 3

[Magnus Melin [:mkmelin]]

Comment on attachment 9352036 [details]
Bug 1815559 - Expand use of "delivered-to" to find identity to catch-all. r=mkmelin

[Approval Request Comment]
User impact if declined: delivered-to not considered for catch-all
Testing completed (on c-c, etc.): c-c, beta
Risk to taking this patch (and alternatives if risky): fairly safe

Comment 4

[Wayne Mery (:wsmwk)]

Comment on attachment 9352036 [details]
Bug 1815559 - Expand use of "delivered-to" to find identity to catch-all. r=mkmelin

[Triage Comment]
Approved for esr115

Comment 5

[Daniel Darnell [:dandarnell]]

Thunderbird 115.3.3:
https://hg.mozilla.org/releases/comm-esr115/rev/5450395f7291