mail mystery

[dep]

this isn't sendmail but it is mail and it is a mystery, and it's driven 
me crazy for two months now.

switched to satellite modem -- wild blue; had to, was on dialup max. 
26.4 with no hope of wire ever actually getting out here. and what 
everyone here said when i was preparing to move here more than two 
years ago is right: dialup is the only thing satellite is better than.

anyway.

since switching to satellite i am having terrible difficulty sending 
mail through one account. it goes fine through others, but this one 
chokes -- usually times out after five minutes or so, then if i try 
again it usually goes through.

it went through fine with the same configuration (password, 
authentication, encryption) on the dialup. only change are satellite 
and insertion of linksys internet gadget/router/firewall/nat box, which 
except for the obvious tightening and password change is pretty much at 
default settings.

using kmail 1.9.5. have probed server for what it wants and have adopted 
its settings, which are the same as it wanted before. and it involves 
only the one upstream server.

i can't really imagine that it's a latency issue, and the isp says all 
is well there, with nothing changed.

anybody have a sense of any diagnostics i could run in hope of figuring 
out where this is going all pear-shaped?
-- 
dep