Error message "550 5.7.1 Connection refused - blocked by Validity"

[#1]

Emails to #@tiscali.co.uk addresses (# = name) are returned with the message below. 

Please request delisting from Validity so that my emails to tiscali are received by the addressees.

####

   * #@tiscali.co.uk

Reason: A message that you sent to the following recipient could not be delivered due to a permanent error. ** The remote server ?? responded with: ** #@tiscali.co.uk ??:?? This message was created automatically by mail delivery software on the server .

Reporting-MTA: dns; avasout-peh-002 [212.159.14.18]
Received-From-MTA: dns; mail.enmail.co [91.204.208.8]
Arrival-Date: Sun, 16 Nov 2025 11:07:06 +0000


Final-recipient: rfc822; #@tiscali.co.uk
Diagnostic-Code: smtp; 550 5.7.1 Connection refused - [212.159.14.18] blocked by Validity - https://senderscore.org/blocklist-lookup/ - OXSEU001_102 - https://postmaster-oxseu.vadesecure.com/inbound_error_codes/#_102

Last-attempt-Date: Sun, 16 Nov 2025 11:07:06 +0000

####

[#2]

Also seeing

Connection refused - [84.93.230.250] blocked by Validity

[#3]

@dave / @plusnettony  - in the absence of knowing a more appropriate name ...

avasout-peh-002.plus.net appears to be on four naughty steps concurrently!

[#4]

Yet another 550 blocklisted error, this time to a hotmail.com address...

Reporting-MTA: dns; avasout-peh-001 [212.159.14.17]
Received-From-MTA: dns; mail.enmail.co [91.204.208.8]
Arrival-Date: Sat, 29 Nov 2025 18:23:23 +0000

Final-recipient: rfc822; xxxxxxxx@hotmail.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=11BC5D7A8DF8D60A] [CO1PEPF000044FC.namprd21.prod.outlook.com 2025-11-29T18:23:24.387Z 08DE2EBD47C6A865]

Last-attempt-Date: Sat, 29 Nov 2025 18:23:24 +0000

Note this from a Force9 address which has NOT been migrated (due "from" 8th Dec).

Please can this be unblocked?

[#5]

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.

[#6]

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.

[#7]

if these 550's are what I think please check for virii and malware, and change your password as a precaution. I then need to know the email address you are sending FROM so I can check if there is something local that I can fix. PM me the from addresses rather than putting them in the public space. Thanks. 

[#8]

I've been having the same error message when I send to one particular contact and would like to  send the details to you plusnettony but don't know how to pm you. Could you provide me with your address please?

[#9]

@Tykebike To send a PM, right click @plusnettony 's name at the side of his avatar - a new window with a 'send a message' option will open.

[#10]

I can't see anything that I can fix, but I've asked about. I'll PM when I hear back.

[#11]

Thanks.

I'm having trouble logging into my account this morning and have changed my password but can't connect to webmail.

Waiting for Advisor to call.

[#12]

Where did you change your password (i.e. on which web site ? )

[#13]

It was on the Plusnet main website. I can log in there but cannot log in to webmail using it.

The advisor thinks that it is due to the migration process and advises me to keep checking by trying to access webmail peridoically throughout the day and then tomorrow morning when the migration should be nearer completion.

[#14]

Which Email brand?

[#15]

It is Force9