[Discuss] Scripting IMAP for large numbers of messages?

[dbarrett at blazemonger.com (Daniel Barrett)]

Has anyone done any scripting to manipulate email on a remote IMAP
server? I'd like to select about 50,000 emails from an Inbox of
~80,000 (say, all emails from 2020) and move them to a different
folder on the same IMAP server. I'm wondering if fetchmail or similar
tools can do this (but am open to other suggestions).

FYI, I've tried this operation in several GUI IMAP clients but they
all either (1) fail for large numbers of messages, or (2) have such a
cumbersome selection process (for "all emails from 2020") that it
would take an hour to highlight all the emails.

Thanks for any tips, or even just a pointer to the best tool(s) for
the job.

--
Dan Barrett
dbarrett at blazemonger.com