On 4/19/2018 starting around 11:15AM CST, our email service had
problems attempting delivery to users that were part of an
internal alias expansion. Normal email boxes that were not part of
an internal alias expansion were unaffected.
The hardest hit legacy users that have email that comes into
[log in to unmask] that instead alias maps to their real mailbox of
[log in to unmask] were the largest set affected.
The email configuration was synced to work correctly on alias
expansions by 12:40PM CDT, and all email services were restored
at this point in time.
Unfortunately during this period, email to this specific set of users
would have been bounced as user-unknown due to this specific weird error.
During our investigation into the root cause, we have found that our
configuration revision control system had a mixture of old and new
configurations in it, and somehow an old configuration was applied to
the running systems.
We forced a clean configuration out of our revision control system,
and the mail systems started behaving like they should after that.
We'll be monitoring everything as we normally do. If you have any
questions please let us know at [log in to unmask]
Doug McIntyre <[log in to unmask]>
-- ipHouse/Green Cloud Technologies --
Network Engineer/Provisioning/Jack of all Trades