I currently have Outlook configured with an IMAP account to download only message headers. The thing is that over the time I have downloaded the body of many messages, as expected, but I would like to know if there's a way to delete the downloaded messages bodies while keeping the headers. Alternatively, if there's a way to delete everything and re-download the headers only I think that would also suit my needs. Thanks.
It might be possible to write a macro for this function.
You can remove the imap account, then configure a (new) account from scratch to download headers only. I don't think there is a built in option to remove the message body and keep the header only.