Forwarded emails from fasthosts being rejected

[oz2net]

My personal domain ( oz2net.co.uk) is hosted at fasthosts. 

All emails sent to this domain are automatically forwarded by the fasthosts mail server (mailserver.livemail.co.uk) to my talk talk email account

Recently most of my legitimate emails  forwarded via Fasthosts (mailserver.livemail.co.uk) to my TalkTalk address are being rejected.

[Philile-TT]

Thank you. Please allow time for the timescale provided for feedback. 

[oz2net]

ok

[Philile-TT]

We will now pass this to a case manager who will complete further diagnostics to fix your email issue and we will contact you on your preferred number in the next 3 working days (not including Saturday and Sunday).

[oz2net]

yes

[Philile-TT]

@oz2net can I use the mobile number that is registered on the account just in case we need to contact you. 

[Philile-TT]

Thank you. 

[oz2net]

done that - I think.

[Philile-TT]

Please privately provide 1 email address that cannot send emails to you. 

[oz2net]

Firefox mostly but also used Chrome

[Philile-TT]

Can you tell me which browser or web browser that you're using?

[oz2net]

First noticed problem Monday 12/01/26.

First noticed when trying to set up account on Prudential and email authentication emails not received.

First error message I have was 12/01/26 @ 23:49

I have included below the last error message received (first part of email addressee removed) today at 02:30 for a message sent Thursday 15/01/26 @ 14:29

*** MAIL DELIVERY FAILURE REPORT ***

The original message was received at Thu, 15 Jan 2026 14:29:05 +0000
from host webmail08.mail.eu.clara.net ([81.171.239.78]:49920 .
          helo=webmail-vh.clara.net).

Subject: Thursday - Claranet test
From: xxxxxxxxxxx@cherrytrees.email

Mail delivery to the following recipient has finally failed:

xxxxxxxxx@talktalk.net
   Last reason: 421 4.2.1
   Explanation: host mx004.tt.xion.oxcs.net [135.125.7.164:25] said: Connection
                deferred - OXSEU001_130 -
                https://postmaster-oxseu.vadesecure.com/inbound_error_codes/#_130
   Final attempt was: Fri, 16 Jan 2026 02:29:21 +0000 (UTC)

   Transcript of session:
   ... while talking to mx004.tt.xion.oxcs.net [135.125.7.164:25]:
   >>> CONNECT mx004.tt.xion.oxcs.net [135.125.7.164:25]
   <<< 421 4.2.1 Connection deferred - OXSEU001_130 -
       https://postmaster-oxseu.vadesecure.com/inbound_error_codes/#_130

Reporting-MTA: DNS; t1-mi4-p00.gem.livemail.co.uk
Received-From-MTA: DNS; t1-mi4-p00.gem.livemail.co.uk

Final-Recipient: RFC822; xxxxxxx@talktalk.net
Action: failed
Status: 4.2.1
Remote-MTA: DNS; mx004.tt.xion.oxcs.net [135.125.7.164:25]
Diagnostic-Code: SMTP; 421 4.2.1 Connection deferred - OXSEU001_130 -
                 https://postmaster-oxseu.vadesecure.com/inbound_error_codes/#_130
Last-Attempt-Date: Fri, 16 Jan 2026 02:29:21 +0000 (UTC)
Final-Log-ID: f0021520G2U8QnZ

[Philile-TT]

Can you provide the date and time when this issue first occurred?

[oz2net]

Yes

[Philile-TT]

Is this the error message? 

 Explanation: host mx004.tt.xion.oxcs.net [135.125.7.164:25] said: Connection

                deferred - OXSEU001_130 -

                https://postmaster-oxseu.vadesecure.com/inbound_error_codes/#_130

[oz2net]

It is

[Philile-TT]

Please ask the sender to check the sent item folder if their email and confirm email being sent is available?

[oz2net]

Yes

An error message is received but not immediately only after many hours

[Philile-TT]

To answer this question: I want you to speak to the email sender and confirm if they were able to sent the email successfully or are they seeing error message when sending it. Is it a yes or no?

[oz2net]

yes

[Philile-TT]

@oz2net so basically you use webmail to access your emails?