1853253 - Message bigger than mailnews.message_warning_size: no warning at File > Send Later time, File > Send Unsent Messages blocked

Status: REOPENED

(MailNews Core :: Composition, defect)

Description

[Jonathan Kamens]

1. Open a compose window.
2. Create a message larger than the setting in mailnews.message_warning_size.
3. Execute the File > Send Later command.
4. Observe how you don't get a warning about the message being too large.
5. Open the error console.
6. Execute the File > Send Unsent Messages command.
7. Observe how Thunderbird says it's sending the message but never finishes no matter how long you wait.
8. Look in the error console and observe the "prompt is undefined" error in MessageSend.jsm.

It's coming from _deliverMessage:

      let prompt = this.getDefaultPrompt();
      if (!prompt.confirm(null, msg)) {

So there are three issues here:

1. No warning when you send the message to your Outbox.
2. Message to fails to send.
3. The user interface doesn't reflect the failure to send and instead just claims forever that it's in the process of sending the message.

The fundamental architectural error here is putting the check on the message size at the point where the message is being sent as opposed to earlier, at the point where it is being "committed" for sending.

Comment 1

[Magnus Melin [:mkmelin]]

Fix landed with bug 1851542 yesterday.

Comment 2

[Jonathan Kamens]

The patch that landed in bug 1851542 is in my opinion only a partial fix. It makes the big message check during delivery from the Outbox work, but I'm arguing here that that's the wrong time to be doing the check. The check should be done before the message is put into the Outbox, because that's when the user is "sending" it. This would be consistent with other checks, e.g., for large attachments, empty subject lines, etc., that are done before the message is put in the outbox. The current behavior is inconsistent.

This is problematic because due to bug 749654 once a message that is too large to send without prompting is encountered in the Outbox, other messages will be blocked from sending if the user is not sitting in front of their computer to respond to the prompt. This can e.g. occur when an add-on (cough cough Send Later with over 100k users cough cough) triggers it when the user is not present.