Diagnostic-Code: smtp; 550 5.7.1... ...part of their network is on our block list (S3150)

stuck · ‎21-05-2009

This just in from Microsoft:

Final-recipient: rfc822; [theCorrectNameHere]@hotmail.co.uk
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). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [Name=Protocol Filter Agent][AGT=PFA][MxId=11BC5D7E2465555F] [DU6PEPF0000B61B.eurprd02.prod.outlook.com 2025-11-30T15:20:55.179Z 08DE2EBF140FD79D]

The original outgoing message was 'To' [someone]@aol.com, 'Cc' [someoneElse]@[domainName].co.uk, [differentPersonAgain]@hotmail.co.uk

Only the @hotmail address generated a bounce, all the others were delivered.

@Townman, which Plusnet staff person needs to be informed of this latest problem with delivery to an MS address?

EDITED TO ADD:

The sending mailbox was a secondary one on my account. It's the same secondary account that's been receiving spam recently and which I griped about earlier today.

Townman · ‎22-08-2007

Yet another thread is not overly helpful, staff are aware of this issue

https://community.plus.net/t5/Email/Server-bad-reputation-Outbound-Mail-Being-Blocked-IP-84-93-230/m...
https://community.plus.net/t5/Email/Error-message-quot-550-5-7-1-Connection-refused-blocked-by/m-p/2...
https://community.plus.net/t5/Email/SMTP-error-550-5-7-1-part-of-network-is-on-block-list/m-p/202663...

It is on the SU escalation list.

In another browser tab, login into the Plusnet user portal BEFORE clicking the fault & ticket links

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.

If this post helped, please click the Thumbs Up and if it fixed your issue, please click the This fixed my problem green button below.

stuck · ‎21-05-2009

@Townman wrote:
It is on the SU escalation list.

It looks like nothing has changed since I started this topic as my latest message to an outlook.com address has bounced with:

Final-recipient: rfc822; [correctNameHere]@outlook.com
Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [212.159.14.17] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [Name=Protocol Filter Agent][AGT=PFA][MxId=11BC67F2CBCD4F37] [DB1PEPF0003922E.eurprd03.prod.outlook.com 2025-12-05T14:30:18.324Z 08DE33F9661525F7]

Last-attempt-Date: Fri, 05 Dec 2025 14:30:18 +0000

stuck · ‎21-05-2009

@Townman @MisterW @plusnettony Any chance that us mere mortal users can be given a clue as to when this block will be removed?

My latest out going message went TO three addresses:

one @gmail - no bounce
one @live - instant bounce
one @outlook - instant bounce

Both of the bounces were as already reported:

Diagnostic-Code: smtp; 550 5.7.1 Unfortunately, messages from [212.159.14.17] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [Name=Protocol Filter Agent][AGT=PFA][MxId=11BC68068772BB1F] [BL6PEPF0001AB4F.namprd04.prod.outlook.com 2025-12-05T15:49:20.944Z 08DE340343E16D31]

Last-attempt-Date: Fri, 05 Dec 2025 15:49:20 +0000