[imp] handling semicolon separated addresses

[Rich Lafferty]

On Mon, Jul 30, 2001 at 06:01:05PM -0400, Jon Parise (jon@horde.org) wrote:
> On Mon, Jul 30, 2001 at 05:56:02PM -0400, Liam Hoekenga wrote:
> 
> > > I missed the start of this thread, but semicolons aren't valid
> > > address separators.  Simple as that.
> > 
> > Acc'd to rfc822, they are:
> > 
> >    http://www.w3.org/Protocols/rfc822/
> > 
> > 	3.4.6. BRACKETING CHARACTERS
> > 
> > 	   There are three types of brackets which must occur in  matched
> > 	   pairs, and which may NOT be nested:
> > 
> > 	       o   Colon/semi-colon (":" and ";") are   used  in  address
> > 	           specifications  to  indicate that the included list of
> > 	           addresses are to be treated as a group.
>  
> I'm not sure if that's the same as an address separator, but,
> either way, if the c-client library doesn't support it, we can't
> either.

It's not. (This is explained much better in RFC2822 than in the
now-obsoleted 822, FWIW.) Commas separate single addresses while
semicolons and colons group sets of separated addresses (including the
null set and set with a single member):

  To: this-thread: jon@horde.org, liam@somewhere.net; rich@lafferty.ca

A mail agent may choose to treat 'jon@horde.org' and 'liam@somewhere.net' 
together -- for example, sending error messages to both addresses if
one fails -- but the addresses are still /separated/ by commas. 

Users run into this, I think, because Outlook (Express?) reportedly
believes that semicolons are syntactic sugar equivalent to
commas. (Could someone with Outlook or Outlook Express test this for
me?)

Common special case: UW mail tools use a null set for a message which
is only Bcc'd:

  To: undisclosed-recipients:; 

(This is already mentioned in two places in the FAQ -- in the admin
faq on the INVALID.ADDRESS.SEPARATOR entry and in the user FAQ in the
"How do I send to >1 person" entry -- but perhaps it deserves its own
entry. Suggestions on what frequently-asked question or
frequently-stated statement the answer goes with are welcome :-) -- in
particular, I'm not sure if this is a "user" issue or an "admin"
issue. I'm leaning towards the former.)

  -Rich

-- 
Rich Lafferty --------------+-----------------------------------------------
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