[imp] Occasional login failures

Joseph Brennan brennan@columbia.edu
Mon, 17 Jun 2002 10:36:26 -0400

--On Monday, June 17, 2002 10:36 +1000 Thu Nguyen <t.nguyen@unimelb.edu.au> wrote:

>> One other thing to add is that we are using the QPopper POP3 server.
>> I wonder whether the way QPopper handles large mailboxes is the source
>> of the problem. Which POP3 server are you using?

The way qpopper works, it copies the entire spool file "user" to another 
file ".user.pop" (not a file rename), and when done it copies the entire 
".user.pop" file back to "user".  With a large spool file, this all takes
time, and in the meantime the pop server rejects connections.  We had
trouble with people who set their pop clients to check every 1 or 2
minutes.  IMP would run POP even more frequently.  It would probably
never work well with qpopper.  To work well you'd have to have 
extremely fast file writes.  It might look OK in testing with a spool
file with only one or two messages in it. 

Joseph Brennan                           postmaster@columbia.edu
Academic Technologies Group, Academic Information Systems (AcIS)