One large factor for me deciding to migrate to dovecot's lda ('deliver') is to use SIEVE, which is under active development and is likely to become a standard (imho). I see no point in creating another lda.
Yeah, with SIEVE support being found in Kmail and addons or plugins for thunderbird and probably others...it kinda paves the way for a standard eh?
What I do see is a need for vpopmail to be able to give 'deliver' any data it needs to do its job (for instance maildir or mailbox, destination location, etc). At some point vpopmail might also include providing SIEVE filtering rules.
The only problem I see at this point in time is how dependent vpopmail is on others to make use of it. vpopmail started out as something to fill out a need missing in the qmail toolchains. Even then, qmail did not have everything (eg: no imap) and it is really nice that dovecot added vpopmail support especially since Sam dropped vpopmail support from courier toolchains.
If vpopmail can take things a bit beyond just say single system user and perhaps be able to handle 1) multi system user virtual domains and 2) massive multi system user management with an appropriate backend like pgsql, then I hope there is incentive for the dovecot guys to keep their relationship with vpopmail and not try to come up with their own management module.
Right now, postfix + dovecot + vpopmail looks pretty neat without getting too many different libraries/frameworks involved. If this can be taken a step further...
!DSPAM:4a9c998632711698363575!
