> What about Cyrus? I am not sure how RFC compliant it is but it supports
> most things.
I think the key feature here was maildir-support. While I'm an advocate of
Cyrus myself, it uses its own format for mailstorage and does not, afaik,
have maildir support.
If maildir as such is a required feature, Cyrus would not be an option.
Much of what can be accomplished with maildir can be done with Cyrus'
format though, but then there's the somewhat proprietary status of its