I have a couple of customers complaining they are unable to send emails
to hotmail - typically they see rejects such as this:
550 SC-001 (BAY004-MC5F11) Unfortunately, messages
weren't sent. Please contact your Internet service provider since part
of their network is on our block list.
It doesn't affect all customers and checking our logs, it appears to
have started 18/1. Prior to that we had no problems delivering
outbound mails to hotmail, since then I see 149 bounces with the
The customers are on dynamic ranges from Swisscom, UPC and e.g. Virgin
(in the UK). Has anyone seen something similar?
Per Jessen, Zürich (-0.1°C)
- your free DNS host, made in Switzerland.