Plusnet mail server blacklisted by Sorbs

[#1]

Hi,
Can anyone help me get this sorted out, 212.159.7.35 is a Plusnet mail server and it seems to be blacklisted.
Error message follows -
5.1.0 - Unknown address error 554-'5.7.1 Rejected. Yours IP 212.159.7.35 are BlackListed by http://dnsbl.sorbs.net'
5.1.0 - Unknown address error 554-'5.7.1 Service unavailable; Client host [212.159.7.35] blocked using dnsbl.sorbs.net; Currently Sending Spam See: http://www.sorbs.net/lookup.shtml?212.159.7.35'

[#2]

is this still the case, second time in 2 days
and i find very worrying as i can no longer trust that my email is getting through...

[#3]

Hi there,
Sorry about the delay, our networks team are just looking at this now. I'll update later on today when I know more.

[#4]

and then the weekend came with no news...
really is a critical issue this ( isn't it ? )

[#5]

Hi there,
We did request removal on Friday though unfortunately haven't yet had a response back I'm afraid. As soon as we do hear anything we'll let you know.