IMAP APPEND or equivalent solution on NetBSD

[Mayuresh <mayuresh%acm.org@localhost>]

I use gmail mailbox as a reliable long term email storage, rather than
a communication id.

I have 100s of classification rules on gmail. But maintaining them using
their UI, within the limitations of their UI is not something I like,
particularly as compared to procmail, which I use on my server.

I am looking for a setup where I use personal server as primary identity,
classify emails using procmail and store chosen few on gmail as a reliable
backup. I want to get rid of classification rules on gmail when doing so.
Essentially I want my procmail rules to decide which gmail folder a mail
should go to.

mbsync/offlineimap could be one of the ways, but I'd prefer to not block
my disk space for this purpose. Also, I have run into reliability issues
with both these tools in the past, where the things had started going out
of sync between the local and the server copy inexplicably.

I read about "imap append" which supposedly can do what I am looking for.

Any suggestions on whether this is useful or anything else that suits
here? And which application to use for the same, would be nice if
it's already available in pkgsrc.

-- 
Mayuresh