Merge pull request #11979 from nextcloud/feat/11976/document-outbox-send-states

feat(outbox): document outbox and send states

Author: miaulalala

user_manual/groupware/mail.rst

@@ -39,6 +39,8 @@ Change sort order
 
 .. note:: This change will apply across all your accounts and mailboxes
 
+.. _mail-scheduled-messages:
+
 Scheduled messages
 ~~~~~~~~~~~~~~~~~~~
 1. Click new message button on top left of your screen
@@ -154,6 +156,29 @@ You can resume your minimized message by clicking anywhere on the indicator on t
 
 Press the close button on the modal or the indicator in the bottom right corner to stop editing a message. A draft will be saved automatically into your draft mailbox.
 
+Outbox
+------
+
+When a message has been composed and the "Send" button was clicked, the message is added to the outbox which can be found in the bottom left corner of the left sidebar:
+
+.. figure:: images/mail_outbox.png
+
+You can also set the date and time for the send operation to a point in the future (see :ref:`Scheduled messages <mail-scheduled-messages>`)- the message will be kept in the outbox until your choosen date and time arrives, then it will be sent automatically.
+
+The outbox is only visible when there is a message waiting to be handled by the outbox.
+
+You can re- open the composer for a message in the outbox any time before the "send"- operation is triggered.
+
+.. note::
+   When an error occurs during sending, three error messages are possible:
+
+   Could not copy to "Sent" mailbox
+      The mail was sent but couldn't be copied to the "Sent" mailbox. This error will be handled by the outbox and the copy operation will be tried again.
+   Mail server error
+      Sending was unsuccessful with a state than can be retried (ex: the SMTP server couldn't be reached). The outbox will retry sending the message.
+   Message could not be sent
+      Sending might or might not have failed. The mail server can't tell us the state of the message. Since the Mail app has no way to determine the state of the message (sent or unsent) the message will stay in the outbox and the account user has to decide how to proceed.
+
 
 Mailbox actions
 ---------------