I'm posting on behalf of someone :-
They have an HTC Desire, and they periodically get the following message when attempting to send out emails:
Warning - Your outgoing server response: 550-Your IP address is on the XBL blacklist! Sending denied.
The phone provides an IP address, which indeed is blacklisted.
This IP resolves to "unknown" somewhere in Germany. We are situated in the UK, as is our email provider.
I have checked with our provider, and the IP of our mail server is not blacklisted (and does not match the one the phone says).
I should add, I am able to send email perfectly well on my iPhone, using (presumably) the same settings. Our computers are unaffected - it is just the HTC.
Does anyone have any advice, or experienced something similar?
I'm reluctant to de-list the IP as I imagine the problem will keep occurring.
Thanks for any insight.