[Rabbit-proxy-users] Delivery failure (rabbit-raplight@abresch.nl)

[<pos...@ab...>]

Your message has encountered delivery problems
to the following recipient(s):

rab...@ab...
(Was addressed to rab...@ab...)
Delivery failed after 1 attempts within 0 minutes
550 5.1.1 User unknown


No recipients were successfully delivered to.