On Fri, May 21, 2004 at 12:54:40PM -0700, Clint Sharp wrote:
LAST, FastUIDL, SlowUIDL. FastUIDL uses the POP3 UIDL command, slow
UIDL uses TOP to parse for Message-ID headers. Obviously all of these
are workarounds for protocol and implementation inconsistencies, and
fetchmail is smarter on the POP3 side (detects if LAST is supported, if
not uses UIDL, if UIDL doesn't work is uses Slow UIDL).
IMO that's an unfortunate choice.
If it were me, I'd use UIDL if it's available: that's the only one supported
officially by the protocol. You could then fall back to LAST, although since
that's nearly 10 years obsolete I think you'd be very unlikely to come
across a POP3 server which supports LAST but not UIDL these days. And then
falling back to checking message-IDs, because a server supports neither UIDL
nor LAST, or because it supports LAST but you don't want to use it?? Seems
like code bloat to me.
More complexity, with or without configuration options, leads to more
confusion amongst users and more noise on this list, and more bugs tickled
in POP3 servers because you're using them in a way which was not intended by
the protocol designers.
For example, the fact that fetchmail picks 'LAST' in preference to 'UIDL'
has caused issues on this list recently; telling the user "add the command
option 'uidl'" fixes it. But that's because fetchmail made a poor choice in
the first place (IMO).
Regards,
Brian.