Given that we have not seen the precise error messages and the context in which they arise one can only make reasonably logical suggestions here. The answer comes in two parts...
- The other IP addresses are not on the PBL
- Therefore such IP addresses do not fall foul of the email host providers INCORRECT interpretation of the PBL^
As advised on several occasions, the PBL would only impact SENDING of emails, not RECEIVING. Sharing the exact (full) error message would help move this forward. What error message do you get when attempting to SEND and what do you get when attempting to READ emails. These are very distinct actions / issues involving different email services.
^Something is not quite as it seems to be here - the PBL (Policy Black List) contains those IP addresses which are not permitted to run a SMTP SERVER for the purposes of RELAYING email. Such circumstances only occur where a customer wants to run their on email host server. In such circumstances, they should use smart relay via Plusnet's SMTP servers for OUTBOUND mail. In other words, these PBL entries DO NOT apply to RECEIVING emails.
My IP address is on the Spamhaus ZEN PBL but that has zero impact on my use of many email hosting services I use (around 5). The description of the above reads...
"Spamhaus PBL is a DNSBL database of end-user IP address ranges that should not be delivering unauthenticated SMTP email to any Internet mail server except those provided for specifically by an ISP for that customer's use"
The important points to note in the above are this relates to...
- Sending not receiving email
- Delivering not submitting email - an email client submits email messages, where as a mail server delivers email
- Unauthenticated use of a SMTP server - which I doubt is the case here
The above points to (a) the problem needs clearer definition and (b) the email hosting provider has a bad implementation of PBL filtering. Who is the hosting provider?
Looking at one of the IP addresses you mentioned before - 87.115.34.100* - it is also on the Barracuda list..
"Listing in the Barracuda Blacklist could indicate any number of issues that need to be addressed in your network including but not limited to: virus-generated spam, poor server configuration, dynamic IP Addresses previously used by spammers, bulk mail sending that does not comply with the CAN-SPAM Act."
Again, this would only impact SENDING of email, not RECEIVING as you report your issue to be.
*.1 / .50 / .75 are also on that list but .25 / .200 are not.
You mentioned RATS listing...
"RATS-Dyna - Probable PC or home connection infected with a Trojan, Bot, or Emailer Program"
What anti-virus / malware protection are you running? But again, this only relates to sending, not receiving.
Looking at the SORBUS black list...
"The SORBS (Spam and Open Relay Blocking System), owned and operated by Proofpoint, Inc., provides free access to its DNS-based Block List (DNSBL) to effectively block email from more than 12 million host servers known to disseminate spam, phishing attacks, and other forms of malicious email. The list typically includes email servers suspected of sending or relaying spam, servers that have been hacked and hijacked, and those with Trojan infestations. In an attempt to provide pre-emptive protection, SORBS also lists servers with dynamically allocated IP addresses."
Notice the the predication is consistently SERVERS not CLIENTS and therefore the reliance of your hosting provider on blocking a CLIENT on your IP address from SUBMITTING an email is entirely wrong. At the very worst here, you have a CLIENT with a dynamically allocated IP address, but proper filtering ought not to present a barrier to your client submitting email messages.
Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.
