I’d like to know if it is possible to delete an email attachment but not the email. Either through webmail or through an app (like Mail on a Mac). Anyone know?
You could forward it and delete the attachment before you send, leaving only the email content.
I know you can do it on the webmail.
Mutt can do this. v from the message index or pager, d on the particular attachment you wish to delete, q once or twice to get back to the index or pager, and $ to sync the mailbox (with default keybindings). It’s possible in Pine as well (v from the message itself to get to the list of attachments, d while selecting the attachment you wish to delete), but I think only if you delete the attachment and then save / delete the message).
Mutt leaves the MIME structure intact, but replaces the attachment with a placeholder.