On Feb 27, 2012, at 10:35 AM, Peter Bowen wrote:
Mails are allowed to have multiple addresses in the from header as
long as they also have a sender header. However, in basic testing, I
have yet to find a MUA that even displays multiple entries for from.
Has anyone seen such a user agent?
Mail.app on OS X displays multiple From: addresses correctly, highlights
them as separate addresses with separate context menus correctly.
So does SeaMonkey. Since the mail component of SeaMonkey is based on
Thunderbird, I presume that means it does as well, although I haven't tried it.
I'm pretty sure Mulberry also supports this, although I don't seem to have a
copy handy to check.
Reply and Reply All respond to just the first of the From: addresses,
while Reply to Sender replies to both of them.
In SeaMonkey both reply and reply-all go to both addresses, which is the
behavior I would expect.
I send out messages with multiple froms fairly regularly. I do make sure to
include the Sender: client (actually, my client does it for me) and I also make
sure to list the primary author first, in case of client misbehavior. I can
think of only one time it caused a problem, and that was with the client Dave
Crocker happened to be using at the time (!).
I receive messages with them less often but occasionally nevertheless.
So it seems to work fine, though given I don't really understand the
intended semantics I'm not sure if they match that.
I could make an argument for those semantics being OK, but I think the ones in
SeaMonkey are a little better.
Functionally, should multiple from
addresses be considered a deprecated feature?
Seems like several pretty popular clients support it.
I'm a bit vague on what their intended use is/was.
The idea is that if a message is written by multiple people, you put all the
author names in the From: field and the name of the person who actually sent
the message in the Sender:. Pretty simple, actually - the problem lies in
building a sensible UI to actually create such messages. And as Randy points
out, a lot of legitimate uses of it run afoul of incompetently designed
security restrictions.
I also frequently get replies - both automatic and manual - when the only place
where my address appeared is in the Sender: field of the original message. (And
no, there weren't any multiple From: addreses involved.) If we're going to
deprecate everything that some client botches, we'll end up deprecating
email in its entirety.
Or maybe we should all switch to using V.A. Shiva Ayyadurai's EMAIL code - no
doubt he got all of this stuff right, what with him being the inventor of it
all ;-) (Sorry about that, but I just couldn't resist.)
Ned