- This command returns exit status 0 if the message was successfully
- added to the mail directory, even if the message could not be indexed
- and added to the notmuch database. In the latter case, a warning will
- be printed to standard error but the message file will be left on disk.
+ This command returns exit status 0 on successful mail delivery,
+ non-zero otherwise. The default is to indicate failed mail delivery on
+ any errors, including message file delivery to the filesystem, message
+ indexing to Notmuch database, changing tags, and synchronizing tags to
+ maildir flags. The <b>--keep</b> option may be used to settle for successful
+ message file delivery.
+
+ This command supports the following special exit status code for errors
+ most likely to be temporary in nature, e.g. failure to get a database
+ write lock.
+
+ <b>75</b> <b>(EX</b>_<b>TEMPFAIL)</b>
+ A temporary failure occured; the user is invited to retry.