An expected delivery to their village pumps was not made. I tried to reproduce at a sandbox, and confirmed.
To reproduce:
- using https://meta.wikimedia.org/wiki/Special:MassMessage
- Send a massMessage to something like this delivery list
- {{target | user = Quiddity (WMF)/sandbox | site = su.wikiquote.org }}
- {{target | user = Quiddity (WMF)/sandbox | site = ml.wikiquote.org }}
- Nothing arrives.
Impact
Message delivery is failing due to a system user conflict.