mbsync for one-way sync, to continually backup whole IMAP account

[Anthony D. <th...@no...>]

Hello,

I'm looking for an app to backup my entire IMAP email account to my local PC.  
This is mainly so that if disaster strikes and my email server is wiped out, I 
won't lose any email.  I'll run the app via cron, every 10 minutes, so that my 
local backup is always up to date.  (And the local backup is on a partition 
that is in turn automatically snapshot-backup'd daily, so even if a server 
error deleted all my mail and then my backup synced that, I can always go back 
to yesterday's copy, etc.)

I use Thunderbird as my main email client, and I've been using OfflineIMAP for 
backup purposes.  But OfflineIMAP syncs both ways, which causes annoying 
issues; for example, when I delete email subfolders in Thunderbird, 
OfflineIMAP automatically re-creates them *on the mailserver*.  Same thing 
when I move mail subfolders.  Or when I read an email in Thunderbird, often 
it'll spontaneously change back to unread status after OfflineIMAP runs.

So what I really want is a one-way sync: an app that mirrors my mail server to 
a local maildir, but never writes anything at all to the mail server (and 
certainly never deletes anything on the mail server).  Basically, I want rsync 
for IMAP -- if I had shell access to my mail server then I would just use 
rsync and be done with it.

Is mbsync suitable for this purpose?  If so, could you be so kind as to write 
a small config file to make it work this way?  I am reading the manpage, but 
I'm not quite understanding the sync/push/pull matrix stuff...

Thank you,

-- 
Anthony DiSante