Prevent movemail from downloading duplicate email over IMAP

[Andrey Portnoy]

Hi,


Can I get movemail to only download new email, as opposed to the entire
inbox every time? By new email I just mean email not previously
downloaded to the destination mailbox, and not necessarily unread
messages. I'm using IMAP and would like to avoid deleting email on the
remote server.

I tried the following to test:

--8<---------------cut here---------------start------------->8---
movemail --max-messages=10 -r -m -v 
'imaps://aportnoy%40fastmail.com:<pass>@imap.fastmail.com:993' FASTMAIL-INBOX
--8<---------------cut here---------------end--------------->8---

This downloaded 10 most recent messages as expected. Running this
command again simply downloads the 10 messages again.

I then hoped that the following command would reuse the existing
messages and terminate quickly, but instead it hangs and seems to
generate a lot of traffic:

--8<---------------cut here---------------start------------->8---
movemail -u --max-messages=10 -r -m -v 
'imaps://aportnoy%40fastmail.com:<pass>@imap.fastmail.com:993' FASTMAIL-INBOX
--8<---------------cut here---------------end--------------->8---

I tried the same approach using POP and got the same results.

Is there a way to get movemail to skip downloading messages that the
destination mailbox already contains?


Thank you,
Andrey.