Re: IMAP APPEND or equivalent solution on NetBSD

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

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.

not clear if i fully understand what youre looking for, but

if you look for a reliable imap sync tool only, take a look at imapsync.

if you want to have a local imap storage / service with the full imap feature set, sieve filters, idle, partitioning, acl etc., i can recommend cyrus-imapd (in combination with procmail or i.e. exim). it offers btw own reliable replication mech between instances.

hth,