Problems sending email to yahoo and btinternet.com

[burnitcouk]

Hi,

When I'm sending emails via catalyst2 SMTP server mail.burnit.co.uk (blueberry.catalyst2.com), I am getting warning bounces and then eventual failure when sending to yahoo and btinternet.com addresses. In both cases the warning message is:

The address to which the message has not yet been delivered is:

xxxxxx@btinternet.com
Delay reason: SMTP error from remote mail server after initial connection:
host mx2.bt.mail.yahoo.com [217.146.188.189]:
421 Message from (84.18.207.66) temporarily deferred - 4.16.50. Please refer to http://help.yahoo.com/help/us/mail/defer/defer-06.html

Following the link seems to indicate that the problem is that the catalyst2 IP has been black/grey-listed. Sending identical email via my normal ISP works fine (but when I'm mobile I need to send via Catalyst2).

Is there something Cat2 can do about this??

Seb