[horde] large number of recipients

[Oliver Schönrock]

I am posting this here because it concerns Turba and IMP.

I am running horde2.1, imp3.1 and turba1.0

Turba1.0 and not 1.1 because it has the To,CC,BCC checkboxes on the search 
page. I am trying to implement rudimentary group support (until the current 
HEAD gets released). I added a Groups field made that field searchable from 
the turba search page.

I also modified turba/templates/search/head.inc, row.inc and oldrow.inc so 
that a the user can click on the "to", "cc", "bcc" headers in the search 
results and this toggle all(!) the respective search boxes via a javascript 
event handler. So it becomes very easy do a search by the new groups field 
(or even succesive searches for groupA or groupB) and the click "to" and 
"send message" to generate an appropriate mail in imp.

So far so good, and it works like a charm, except when you have "large" 
groups.  You end up with a truncated (to about 3kB or roughly 80 email/real 
name pairs) list of addresses in the IMP "to" field. Since the addresses 
are passed to compose.php via the url, i though that this could be the 
limit. So I rewrote head.inc so it uses "post" rather than "get" to pass 
the info to imp/compose.php. Although this worked great and is probably 
better code anyway, it made no difference to the large groups problem 
whatsoever.

Then I discovered that Opera and IE truncate the address list at different 
points. I played around with the "maxlength" attribute of the "to" field, 
but no success.

So....It seems there are some limitations for large recipient list in the 
current code in two areas:

- the url passing of addresses (which my mod fixes)
- the length limit of the to field in IMP (the extent of which appears to 
be browser dependent)


So my questions are:
- How can I support mails to long lists of people in groups? (one option is 
a mailing list but this requires the integratuon with a separate mailing 
list db)
- Is there also a limitation in SMTP/Sendmail for very long recipient 
fields? if there is then the above may be the only real option
- will these limitations become more important in the next release of 
turba/imp which is supposed to support groups.

Thanks in advance


Oliver Schönrock