Frank Peters posted on Tue, 23 Aug 2011 19:46:29 -0400 as excerpted:

> Actually I much prefer Sylpheed over all other email clients and I use
> it almost exclusively.

Interesting.  I had been a kmail user for nearly a decade, since 
switching from MS and MSOE back in late-2001/early-2002 (when MS pushed 
me off with eXPrivacy), but after adopting a wait-and-see attitude toward 
akonadi, with 4.6 I waited and saw enough, and switched to claws-mail in 
time to avoid emerging kmail for kde 4.7.

Way back when I was switching from MS and choosing my apps then, I had 
tried sylpheed and the (then) sylpheed-claws, but something, I've long 
forgotten what, wasn't quite right for me, and I ended up on kmail 
instead.  Of course that was a long long time ago, and features, etc, 
have rather changed, so whatever was the problem then very likely isn't 
one now.

Anyway, I've been extremely impressed with claws-mail, using it both for 
mail, and, in another instance (I had to set $HOME and $TMPDIR in a 
wrapper script so it didn't try to use the mail instance) with the rss-
reader plugin, for feeds (as a replacement to akregator, which seems to 
have fallen well behind the times in its ability to filter, etc, as well 
as the fact that while it doesn't use akonadi directly, it uses kdepim-
common-libs, which pulls in akonadi even if nothing's really using it).

I've long used pan for news (nntp), but after seeing how well claws works 
for mail and for rss and atom feeds, I'm thinking I might try it for news 
as well, at least for my text groups.

Anyway, given that claws originated as the development version of 
sylpheed, I've wondered what the practical differences are.  I did try 
sylpheed, but other than seeming to be a slightly older version of claws, 
with correspondingly slightly less features, etc, and the rather more 
marked Japanese origin (the homesite is in English/Japanese, but some of 
the more info links are only Japanese), I didn't see a lot of difference.

So I've been wondering what the rest of the story might be, and why 
people, at least non-Japanese (no offense, just that info's easier to 
absorb if it's not filtered thru google translate or the like), might 
prefer sylpheed to claws.  If you could shed some light on either the 
difference in emphasis and split, or why you personally prefer sylpheed, 
I'd be quite interested. =:^)

(FWIW, the only guess I have is that perhaps with the switch to gtk2, the 
sylpheed dev preferred not to enable customized hotkeys to the degree 
that claws has, since as I found out, /every/ and I really do mean /
every/ single bit of functionality in claws seems to be exposed with a 
possible hotkey customization.  While kde is pretty good with hotkey 
customization most of the time, it doesn't expose /every/ little function 
as a hotkey, as claws seems to!  I'm sort of familiar with how the gtk2 
hotkey dump functionality works from pan, too, but claws really does seem 
to take configurable hotkeys to all to an /entirely/ different level.  
It's possible the same general idea applies to the filtering and external 
commands functionality, too, as claws seems to be very good with that as 
well. But that's only a guess.)

> But there are times when I need to communicate to someone that is using
> MS Outlook on the other end and for that purpose I will pull thunderbird
> out of the closet and compose a message in HTML format.  MS users can't
> seem to appreciate, or even understand, anything else.

Argh!  If they want to read my mail, they can very well read it in plain 
text, or add the HTML themselves (as effectively happens when they read 
it in webmail, as my folks do).  I'm sure if it hasn't already been done, 
someone could come up with a script that adds tags either randomly or 
based on some scheme, changing fontface, fontsize, fontcolor, adding 
graphics including graphical smileys, etc.

FWIW, one of the things that's so great about claws is its html-filtering 
mode, which reduces everything, including all those feeds which obviously 
in XML, into plain text, and does a rather good job at it if I DO say 
so!  I was thinking about using gwene.org feeds2news for the feeds, since 
I already use gmane.org lists2news for my mailing lists, and then using 
pan, but because the feeds are XML and pan simply parses it as plain 
text, raw tags and all, that didn't work well AT ALL when I tried it.  
But by then I was already using claws for mail, and noted its html2text 
mode, so decided to try it.  I've been VERY pleasantly surprised with the 
results, AND the speed, so far. =:^)

Anyway, if claws can do so well at deHTMLifying things, certainly a 
script could be designed to HTMLify things as well, for those who wished 
it that way.  I imagine it could even be designed to randomly insert 
various webbugs, other spyware, script-aided exploits, etc. just like the 
real thing, so people could REALLY feel at home with their
candy-over-security choice! =:^\

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman