topic Re: Unable to send e-mails to Outlook e-mail account users in Email

Unable to send e-mails to Outlook e-mail account users

ebforum — Sun, 07 Dec 2025 08:43:58 GMT

Although this problem has been mentioned previously in e-mail problem threads, I thought I'd start a new thread to see if anyone, superusers or whoever, can engage with technical staff at Plusnet/Greenby to implement a solution. This problem is causing me significant disruption.

e-Mails to Outlook.com addresses from my PC using Outlook365 as part of Office365 suite are being bounced with the following:

Reporting-MTA: dns; avasout-ptp-002 [84.93.230.235]

Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [84.93.230.235] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150).

Surely Plusnet/Greenby tech staff can engage with Microsoft tech staff to implement an unblocking?

Re: Unable to send e-mails to Outlook e-mail account users

offscotland — Sun, 07 Dec 2025 12:53:07 GMT

Using Webmail I got an identical error reported when trying to reply to a hotmail.co.uk address earlier today Sunday 7th Dec at 11:01hrs

The system was happy enough sending to the same account on Friday...

Re: Unable to send e-mails to Outlook e-mail account users

stuck — Sun, 07 Dec 2025 12:58:09 GMT

@ebforum wrote:

Surely Plusnet/Greenby tech staff can engage with Microsoft tech staff to implement an unblocking?

According to @MisterW here:

https://community.plus.net/t5/Email/Diagnostic-Code-smtp-550-5-7-1-part-of-their-network-is-on-our/m-p/2031382#M56071

they are.

Re: Unable to send e-mails to Outlook e-mail account users

Townman — Fri, 12 Dec 2025 14:55:54 GMT

@ebforum wrote:

Although this problem has been mentioned previously in e-mail problem threads, I thought I'd start a new thread.

Please don't it is not helpful, it is just another mole hole to whack with the same hammer.