Balsa + libESMTP patch

[Brian Stafford <balsa stafford uklinux net>]

Hi Pawel and list,

Attached is a patch which replaces the use of sendmail and
Balsa's original SMTP client with libESMTP.

You will need to obtain at least version 0.6.1 of libESMTP
from http://www.stafford.uklinux.net/libesmtp/ to use this
patch.

To set up the patched version of Balsa, go to
Settings/Preferences/Mail Servers and specify the remote SMTP
server mail is submitted to.  The syntax is hostname[:port].
Since libESMTP defaults to port 587 rather than 25 you will
most likely need to specify the server as something like
'localhost:25'.  User and Pass Phrase must be specified if the
SMTP server requires authentication.

libESMTP implements an SMTP client which supports many SMTP
extensions including PIPELINING and AUTH.  The use of PIPELINING
in conjunction with libESMTP's internal buffering will
significantly reduce the number of round trips, both at
protocol and TCP level, with the server compared to Balsa's
current SMTP client.

As currently implemented the patch does not support requests
for Delivery Status Notifications even though libESMTP supports
this SMTP extension.  The effort needed to implement this would
be similar to that for the Message Disposition Notification
patch.  I will do this ASAP (unless someone else beats me to
it :-)

regards
Brian Stafford

patch-balsa+libesmtp.gz