[Dovecot] considering dovecot

[Rick Hazey]

Hi all.

I'm making a case to use Dovecot over Courier and would like some  
feedback. I've searched the web extensively and have been unable to  
find any hard information regarding Dovecot's IMAP performance. I've  
got some pressure to use Courier but my gut tells me that Dovecot  
should be much faster. In particular, I will have typical users with  
mailboxes exceeding 10,000 emails and in some cases up to 100,000.  
Courier might be the "safe" choice but I'm not confident it can  
handle inboxes with that many messages. Dovecot, with its indexes,  
should be much, much faster. Can anyone point me to some benchmarks  
or production uses of dovecot that bear this out?

 From my research, Courier maildrop appears to be what I need for  
local delivery. Is it possible to use Maildrop for local delivery  
with Dovecot? Or is the Dovecot LDA needed to update the maildir  
indexes?

I also need the capability for users to set their own vacation  
messages via a web page. Maildrop looks to handle this easily (by  
allowing me to link the maildrop filter to a file with the vacation  
message) but I don't see similar capability with the Sieve plugin. I  
do see where I can create a vacation message with Sieve but the text  
of the message seems to be required to reside within the Sieve  
script. Perhaps I'm missing something?

Any feedback would be greatly appreciated.