For the impatient:
Patch for Pine 4.63, 4.64
Pine source
FAQ on patching pine

This patch adds an option to Pine that deletes all attachments from messages when you save them. Both MIME multipart attachments and standard file attachments are deleted. They’re replaced with a message that describes the deleted attachment, just like manually deleted attachments.

If this feature is enabled, the Delete and Undelete commands in the Attachment Index screen are replaced with the Preserve command. You may Preserve individual attachments, and they will not be deleted when their message is saved.

As background, email usage has evolved and large attachments are now common. Also, modern mailers often send the same message in both HTML and plain text, using MIME multipart attachments. This means that attachments can quickly take up a large amount of space in your mailbox. If you have a quota on your mail server, this feature can help prevent attachments from using up your quota.

This patch was inspired in part by a post to the pine-info mailing list.

Feel free to email me with feedback or bug reports.