I've just had a 550 reject from a mail to Tiscali.  I know it's their 
problem but...  Just a warning to others here, before support can look 
into it :-( 

<Q>
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  ????@tiscali.co.uk
    SMTP error from remote mail server after MAIL FROM: 
<???@earlsway.co.uk> SIZE=4003:
    host mx6.uk.tiscali.com [212.74.100.152]: 550 mail not accepted from 
blacklisted IP address [81.187.30.51]
</Q>

-- 
John W
To mail me replace the obvious with co.uk twice

John D.W. wrote:
> I've just had a 550 reject from a mail to Tiscali.  I know it's their 
> problem but...  Just a warning to others here, before support can look 
> into it :-( 
> 
> <Q>
> A message that you sent could not be delivered to one or more of its
> recipients. This is a permanent error. The following address(es) failed:
> 
>   ????@tiscali.co.uk
>     SMTP error from remote mail server after MAIL FROM: 
> <???@earlsway.co.uk> SIZE=4003:
>     host mx6.uk.tiscali.com [212.74.100.152]: 550 mail not accepted from 
> blacklisted IP address [81.187.30.51]
> </Q>

A colleague with an AAISP account has also had this problem. Support have 
been informed. A case of blacklisters not checking their facts as usual, I think.