mozilla/basket — pull request #108 by pmclanahan (2014-09-29 19:13:21+00:00)
Title: No longer raise errors for missing message IDs.

This was causing failures due to an exception being raised
attempting to send a welcome message before adding the record to
master subscribers. Also we were trying to send a message to a user
that may well not have been in MS which would be an error.

@Osmose r?