498480 - Support group addresses from RFC 2822.

Status: RESOLVED DUPLICATE of bug 110605

(Thunderbird :: Mail Window Front End, defect)

Description

[Blake Winton (:bwinton) (:☕️)]

Attachment: The email to a group recipient.

As part of Bug 496440, I'm scanning for email addresses with a ":" in them, assuming that they're part of an empty email group, and thus removing them for the purposes of figuring out how many people I'm trying to reply to.

But that's really only a heuristic, since we could have an email group with more than zero addresses in it, which would break my code.

To see what would happen in that case, I grabbed the To: line straight from RFC 2822 (http://www.faqs.org/rfcs/rfc2822.html) Section A.1.3. Group addresses:
To: A Group:Chris Jones <[e-mail]>,[e-mail],John <[e-mail]>;
emailed myself with it, and saved it as the attached .eml.

I'm not really sure what I thought we should do with this.  Currently, we think
the message has three addresses:
A Group:Chris Jones <[e-mail]>
[e-mail]
and
John ; <[e-mail]>
but that doesn't seem quite right.

The RFC says:
In this message, the "To:" field has a single group recipient named A Group
which contains 3 addresses.

If we changed it to three addresses; "Chris Jones <[e-mail]>",
"[e-mail]", and "John <[e-mail]>"; I think we could justify that
behaviour.  It might be better for my Reply-All patch if we could somehow treat
the group as a single address or address group, which had a list of addresses
within it, but I suspect that would have much larger ramifications, and so
might not be worth doing.

As a couple of notes, the Mail app on my iPod touch does exactly the same as what we're currently doing.  GMail gets it right, as I'll show in a future screenshot.

Comment 1

[Blake Winton (:bwinton) (:☕️)]

Attachment: Our current behaviour.

Note the incorrect first and third address, and the arguably-incorrect Reply All button.

Comment 2

[Blake Winton (:bwinton) (:☕️)]

Attachment: GMail's current behaviour.

Note the lack of "A Group:" and ";", and the fact that "Reply" replies to all three addresses.

One other thing to note is that with the exception of the empty group "undisclosed-recipients:", I've basically never seen a group recipient in the wild.

Comment 3

[David :Bienvenu]

the interface is defined here:

http://mxr.mozilla.org/comm-central/source/mailnews/mime/public/nsIMsgHeaderParser.idl

and implemented here:

http://mxr.mozilla.org/comm-central/source/mailnews/mime/src/nsMsgHeaderParser.cpp

my first thought would be perhaps extend the interface to parse groups and get their sub-addresses by adding new methods, and make the old methods simply strip out groups:..

Comment 4

[Blake Winton (:bwinton) (:☕️)]

Attachment: OS X's Mail.app's current behaviour

Just for completeness, I tested this with the Mail client in Mac OS X 10.5.7, and found that it did the same thing that TB does.