Gnus sending speed?

[ross@rosslaird.info (Ross A. Laird)]

This has probably been asked and answered many times, but I was not able
to find anything immediately relevant by searching. Here's my challenge:
Gnus opens a STARTTLS connection and sends mails without difficulty, but
each instance of sending takes about 20 or 30 seconds. That's a while to
wait, when in a given email session I might send 20 emails (so, as much
as 10 minutes of waiting overall!).

Some of this delay may be due to my remote IMAP server, which is a bit
slow (I think that Thunderbird hides this slowness by closing the send
window before the mail is fully sent; whereas Gnus just waits). I use a
remote sending server, and a local Dovecot server for downloading mail
with offlineimap, but I don't use the local server for sending -- I've
been told that it's problematic to do so.

I assume that sending through Dovecot would be much faster -- but is
that not going to create problems with online mail services? And, if I
am stuck with the remote IMAP server for sending, is there any way to
speed up Gnus so that it releases the sent mail buffer sooner, or keeps
the IMAP connection open ... or something?

Ross

-- 
Ross A. Laird, PhD
www.rosslaird.com