Emails bouncing back to hotmail live and outlook accounts

[#1]

Hi there,

We recently noticed that hotmail/outlook and live email addresses are bouncing back to us.

We use windows live mail client, with our own server details.

We have filed a report with windows hotmail/live and outlook to check why this is happening.

In the meantime I checked if any of our ip addresses are black listed, and behold - they are.

LISTED	SORBS DUHL	91.125.243.78 was listed  Detail	3561	94	Ignore
LISTED	Spamhaus ZEN	91.125.243.78 was listed  Detail	300	94	Ignore

Going to Spamhaus ZEN: This is the code showing up:

Ref: PBL986092

91.125.0.0/16 is listed on the Policy Block List (PBL)

Outbound Email Policy of Plusnet Plc for this IP range:

It is the policy of Plusnet Plc that unauthenticated email sent from this IP address should be sent out only via the designated outbound mail server allocated to Plusnet Plc customers. To find the hostname of the correct mail server to use, customers should consult the original signup documentation or contact Plusnet Plc Technical Support.

What does that even mean, and where do I go from there?

[#2]

My understanding of this is that SORBS have listed your IP Address as a Dynamic address.  If I remember correctly @bobpullen has previously said that Plusnet ask from time to time for certain blocks of IP Addresses to be removed, but after time SORBS add them back in.

I think the recommended way is to have your mail server Smart Host to PlusNet's Relay servers (or those of another host), which would get around this issue.

[#3]

@x8r,

I've had to create a ticket on your account to clarify a few things. If you could have a look for me and let me know your thoughts.