Or, don't use imaps:// sources. Ruby's IMAP library otherwise fails in
this somewhat uninformative manner.
+P: When I run Sup remotely and view an HTML attachment, an existing
+ Firefox on the *local* machine is redirected to the attachment
+ file, which it can't find (since it's on the remote machine). How do
+ I view HTML attachments in this environment?
+
+S: Put this in your ~/.mailcap on the machine you run Sup on:
+ text/html; /usr/bin/firefox -a sup '%s'; description=HTML Text; test=test -n "$DISPLAY"; nametemplate=%s.html
+