[BlueOnyx:25245] 451 4.6.0 Alias expansion error

[f.kaegi at fairtalk.com]

Hi

Since a few days we occasionally are getting a "451 4.6.0 Alias expansion
error" when sending mails to email aliases that before worked perfectly
well. 

Gmail for example writes: Delivery incomplete. There was a temporary problem
delivering your message to xxx at xxxxx.xx. Gmail will retry for 47 more hours.
You'll be notified if the delivery fails permanently.

What could be the reason?

Best wishes
Felix




-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.blueonyx.it/pipermail/blueonyx/attachments/20211215/027b8313/attachment.html>