E-mails to hotmail.com addresses being bounced (blocked dynamic IP address)

[#1]

In the last week or so I have had a problem with my e-mails being bounced from hotmail.com addresses (when those to other addresses get through without problems). The problem seems to relate to my (Plusnet) dynamic IP address being blocked because it is "listed in the PBL" with the information: "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." (This information from https://www.spamhaus.org/lookup/ on the IP address).

My e-mails are being sent to the SMTP mail server for my own domain, which is hosted with Falcoda Internet, but are authenticated using SSL, so do not appear to fall in the scope of the policy described above. Until about a week ago I was having no problem sending messages to hotmail.com.

Is this caused by hotmail over-interpreting the Plusnet policy, or is there something I need to do in configuring the SMTP server?

The problem looks as if it may be related to one discussed last year at https://community.plus.net/t5/Business/Emails-bouncing-back-to-hotmail-live-and-outlook-accounts/td-... though details of any resolution are not discussed there.

[#2]

In the thread you linked to the user had their own mail server which was sending the mail, which is why their IP address becomes an issue.  If you are sending via someone elses mail server as you say then your IP address of your connection shouldn't come in to play at all.  The sending IP address would be that of Falcodas smtp server(s).

[#3]

Thanks for your comments on this. I've actually now been able to resolve the issue by changing the Falcoda SMTP mail server I connect to (at their suggestion). The SMTP server under my own domain name appeared to be just an alias for one of theirs (which seems, as you suggested, to have been causing the problem) but swapping to a direct connection to another of their SMTP servers has resolved the issue.

Their original suggestion of turning off my Plusnet router and turning it back on again (in order to get a different dynamic IP address) did not work. Though all the dynamic IP addresses I tried were reported by Spamhaus as blocked, from your comments it looks as if that was not the direct cause of the problem.

Many thanks for your help.

[#4]

Great.  I'm glad you got it sorted.  Most ISP IP addresses will appear on Spamhaus as blocked (including many "static" addresses).  Plusnet have asked for certain address ranges (for static addresses) to be removed, and they do for a while before often being put back on again. That is one reason why it isn't a good idea to run an SMTP yourself (without Smart Hosting to a more trusted SMTP server).

As you've discovered though, that had no bearing on your problem.