[imp] imp with courrier imap is too slow

[Alain Fauconnet]

On Sat, Dec 04, 2004 at 01:50:10PM -0600, Dan H wrote:
> I don't know if this is the default or not but are you using a Maildir 
> format or
> an Mbox format?  Maildir is wonderful.  Much faster than Mbox in my 
> opinion.

As far as I know Courier IMAP only does Maildir, so there's no choice.

>  I
> get tons of spam every day but I don't experience a bit of lag.  Granted I
> don't get 1200 pieces but it isn't uncommon for me to go into my mailbox and
> have over a hundred new messages.  And since I'm terrible about putting my
> messages in folders I often have a few hundred messages total in my inbox.
> Never have a problem with speed when using Courier.

Neither did I, or at least they  were  much  less  severe  than  using
UW-IMAP  and  mbox.  I  once  managed  a  busy 80K mailbox mail server
running off a not-so-hot Sun E420 server  with  software  RAID-1  SCSI
storage   of   old   technology,  definitely  not  an  impressive  I/O
bandwitdth.  The  system was busy but reasonably fast, even under spam
attacks.  IMP itself was running off a separate commodity hardware PC.
No IMAP proxy. Many users did have in excess of 1,000  messages  in  a
single mailbox.

So  basically,  IMP  running  in front of Courier IMAP should give you
good performance. If it doesn't, then you have a bottleneck somewhere.
You  don't  give  any  information about the underlying hardware, O/S,
filesystem etc. I'd bet that your bottleneck is disk I/O  or  lack  of
memory     causing    filesystem    caches    to    be    ineffective.

You're not accessing mailboxes over  NFS  are  you?  This  is  a  real
performance killer.

Greets,
_Alain_