[Dovecot] POP3 Performance

[Timo Sirainen]

On 16.3.2012, at 19.49, Kelsey Cummings wrote:

> On 03/16/12 06:07, Timo Sirainen wrote:
>> Maildir isn't very good for POP3, especially if the POP3 clients delete the mails after download. With Dovecot you could look into switching to multi-dbox format, which would have much better performance.
> 
> Timo, can you explain why Maildir isn't a good for POP3 in this context?

Compared to mbox/mdbox: It needs to read and delete multiple separate files, which is typically much slower than reading and deleting a single file.

> Another thing our existing POP3 servers did was batch all of the deletes until after the +OK... was returned from quit.  This doesn't reduce server load but has the impression of creating faster response times to the clients.

You mean deleting the messages after +OK, instead of before? Does it really make a difference?.. Dovecot can reply with -ERR to QUIT if deletions failed for some reason.