RexxMail saves only the body text and headers of sent mail messages, since it assumes that the originals of any attachments will be kept elsewhere on the system.
If RexxMail finds a 'RunAttachOut' command line in the 'settings.txt' file, this will be run in the attachments folder before dispatch, e.g. to preprocess the contents of the attachments folder.
The attachments folder is automatically closed when the mail message editing session is terminated, i.e. when the mail message text file is saved and closed.