🚀 go-pugleaf

 > > I am trying to send a message with vm-mail.  The message includes an
 > > FCC line to a folder ~/mail/sent (set from mail-archive-file-name).  I
 > > also happen to be currently visiting the "sent" folder.  vm-mail-send
 > > fails to send the message or save it in the file and gives an error
 > > "Buffer is read-only: #<buffer sent>".
 > 
 > This looks like a bug. I have vm-visit-when-saving's value 0, and it still
 > causes this error. When vm-visit-when-saving is neither t nor nil, it
 > should append to the buffer when visited and append to the file if not.

Using FCC is not "saving".  I don't support the use of FCC.  If
you want a copy of all your outbound messages, the right way to do
it is to set mail-self-blind to t.