slow

[Iv Ray]

I have been using Postfix + Cyrus IMAP on FreeBSD for about 2-3 years  
and the performance has always been good.

The last months, however, the speed somehow deteriorated.  
Squirrelmail, for instance, takes longer than usual to go to display  
the folders and messages after login, and to go to next page (sorting  
is off) - 20-30 seconds. E-mail client like OS X Mail takes also  
longer to open IMAP accounts on this server, than on other servers.

The server is 2 GHz with 2 GB RAM and 2 x SCSI HDDs in RAID 1, load  
average is normally around zero. The server hosts less than 100 e-mail  
accounts, most with less than 10 MB of e-mails, and a few with 1-2 GB  
of e-mails. These parameters haven't really changed over the last 2-3  
years, so I do not expect the delay to come form there.

I did "rebuild" of all mailboxes a couple of times, but without success.

Could someone give me a hint what might cause the slowness and/or  
possible debugging steps.

Thank you very much,
Iv