[Users] Can't send, queue or save message

[John Jason Jordan]

I am trying to send a message from my university account, which I
access with Claws 3.13.2 on Xubuntu 16.04 with IMAP4, to another
university student. When I send, send later, or save the message I get
ERROR: Cannot queue message for sending, or ERROR: Cannot queue
message, or ERROR: Cannot save draft.

I poked at everything I could find, but no luck. I need some clues.