788188 - When message send fails, compose window is closed and message is copied to Sent Mail folder

Status: RESOLVED DUPLICATE of bug 780124

(Thunderbird :: Message Compose Window, defect)

Description

[Matt Carter]

Attachment: Snapshot of pop-up window showing message send failure

My SMTP server (plus.smtp.mail.yahoo.com) is very unreliable.
Sending a message fails about 20% of the time with the following pop-up window:

  Alert
  (!) An error occurred while sending mail.  The mail server responded: Resources temporarily unavailable - Please try again later.  Please check the message and try again.
  [ OK ]

(I have attached a snapshot of this pop-up window.)

The message is _not_ actually sent when this happens.  (I have confirmed with the intended recipient.)

The problem is that when the message send fails as described above, the message is copied to the "Sent Mail" folder and the message composition window is closed.

What _should_ happen when sending a message fails is:
  - The message composition window should remain open.
  - The message should _not_ be copied to the "Sent Mail" folder.

This desired behavior was how it used to work.  This broke at or shortly before version 15.