topic Re: Email could not be delivered in Email

Email could not be delivered

Woody179! — Wed, 23 Apr 2025 21:34:11 GMT

Hi,

I am having a problem sending email to a Tiscali email address. When I try to send an email to this account I receive a email stating Undelivered Mail Returned to Sender. The full message I receive is below (email address is blanked out but I will put the email address in my private notes).

This is the mail system at host mx-out.tt.xion.oxcs.net.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own text from the attached returned message.

The mail system

host mx003.tt.xion.oxcs.net[135.125.7.163] said:

550 5.5.1 Recipient rejected - OXSEU012_403 -

https://postmaster-oxseu.vadesecure.com/inbound_error_codes/#_403 (in reply

to RCPT TO command)

Re: Email could not be delivered

angelique-TT — Thu, 17 Apr 2025 09:25:16 GMT

Good morning @Woody179! . Please confirm if this happens when trying to send an email to tiscali email addresses only or all email addresses?

Re: Email could not be delivered

Woody179! — Thu, 17 Apr 2025 09:34:22 GMT

Good morning @angelique-TT , the problem only happens with this Tiscali email address, I can send to other email accounts at TalkTalk.net and other addresses fine.

Re: Email could not be delivered

siphosethu-TT — Fri, 18 Apr 2025 07:18:09 GMT

Hi there Woody179!, please confirm how you are accessing your emails, whether it's via app or webmail. Thanks

Re: Email could not be delivered

Woody179! — Fri, 18 Apr 2025 18:02:09 GMT

Hi,

I am mostly using Outlook 365 but have also tried using webmail, I must also point out that everyone else I send an email to, they receive it fine, it is only this one email account that returns the problem.

Re: Email could not be delivered

siphosethu-TT — Mon, 21 Apr 2025 07:23:26 GMT

Hi there Woody179, from what you stated above I take it you only have a problem with one specific email your unable to send too, correct? Thanks

Re: Email could not be delivered

Woody179! — Mon, 21 Apr 2025 19:08:26 GMT

Hi @siphosethu-TT , yes that's correct, just this one Tiscali email address has the problem, I can send to all other email addresses fine, including others that are on tiscali.co.uk.

Re: Email could not be delivered

siphosethu-TT — Tue, 22 Apr 2025 07:25:40 GMT

Thank you for confirming that for me, please also confirm if you are currently at home so we're able to run diagnostics on this and hopefully have it sorted as soon as possible. Thanks

Re: Email could not be delivered

Woody179! — Tue, 22 Apr 2025 14:55:12 GMT

Hi,

Yes I'm at home now.

Re: Email could not be delivered

siphosethu-TT — Tue, 22 Apr 2025 15:03:34 GMT

Thanks for confirming, I'll just need you to contact our full fibre team using the number I've provided below or if you prefer you can use the link directing to live chat and they will assist you in getting this fixed as soon as possible. Thanks

03451720074

Opening Hours:

Mon-Fri: 9am-7pm; Sat: 9am-6pm; Sun: closed

https://community.talktalk.co.uk/t5/FutureFibre/bd-p/FutureFibre

Re: Email could not be delivered

Woody179! — Wed, 23 Apr 2025 14:27:48 GMT

Had a live chat yesterday, lasting over an hour, the agent I spoke to was adamant that the email I'm trying to send too must be blocked, I've checked with my Father again, taken over his computer and double checked, there is nothing on his side rejecting my emails. Also If I block an email on my side, the email in question just goes into my spam/junk folder, so this can't be as simple as a blocked email address.

Re: Email could not be delivered

Billx — Wed, 23 Apr 2025 15:28:40 GMT

Hi, @Woody179!

Which blocking method did you check/use, in your father's and your computer?

To block an email address, one needs to go via TalkTalk webmail, via the browser.

Click the Cogwheel

Click All settings

Scroll down, until you see 'Access Lists'

Click 'Access Lists'

Click 'Blocklist'.

Here, you will see, if any incoming email address is already blocked, or block a new email address.

In a similar way, if an incoming email address is going to the SPAM folder,

You can Click the 'Allowlist', on the left,

and there, force the email address to be allowed, and not end up in SPAM folder

EDIT: I am not 100% sure, this 'Allowlist method will work to stop emails from going to SPAM

If it doesn't, when you next message, I will give an alternative method.

Bill

Re: Email could not be delivered

Woody179! — Wed, 23 Apr 2025 17:30:57 GMT

Hi @Billx ,

Yes, that is the way I checked to see if the email address had accidently been blocked.

Thanks,

Re: Email could not be delivered

Woody179! — Wed, 23 Apr 2025 18:10:13 GMT

Just been researching the error code and it looks like it is a problem with the recipients email server.

The 550 5.5.1 recipient rejected error means the recipient's email server has rejected the email because it believes the email address is invalid or the server cannot deliver to it. This often indicates an issue with the email address itself, or a problem on the recipient's mail server.

Re: Email could not be delivered

Billx — Wed, 23 Apr 2025 20:26:00 GMT

"Just been researching the error code and it looks like it is a problem with the recipients email server."

Now the recipient is your father, and his email address is a tiscali.co.uk email address

I assume yours is a talktalk.net address or a tiscali.co.uk address

So you both have the same email server?

The error you received, from the OX people:

---

_403
550 5.5.1 Recipient rejected
This mailbox does not exist here.
These errors should be treated as an "unsubscribe" by the sender, if a bulk mailer.

---

This is ambiguous, I don't understand what it means.

Does 'Recipient rejected' mean 'rejected by the recipient'

or does it mean rejected within your own settings, and you don't want any emails to go to that address?

It seems the OX people translate a previous code, 550 5.5.1 to their own code _403

I assume it means your father's mailbox (email address) does not exist.

Oh, by the way, it seems the full email address that is the subject of this thread, is still visable to us, in your first post

To delete it, edit your message and delete the '@' before domain.

Bill

Re: Email could not be delivered

Woody179! — Wed, 23 Apr 2025 20:38:28 GMT

Hi @Billx

My Father says he still receives other emails on that account and I am sending an email to him via a talktalk.net address. I thought I had removed the address but just found if you click on it, it's still there, there is no edit option on my post - presumably because its a few days old - hopefully a moderator can remove it for me - but thanks for pointing it out.

Re: Email could not be delivered

Billx — Wed, 23 Apr 2025 20:52:02 GMT

@Woody179!

I just tested one of my own-originated threads.

There was an edit function

I added 1 character to it, to the original post.

And it indeed changed it and saved it correctly.

Bill

Re: Email could not be delivered

Woody179! — Wed, 23 Apr 2025 20:52:50 GMT

Hi @Billx

I clicked on the three dots on my first post but the pop up didn't have any edit option - see below

Re: Email could not be delivered

Billx — Wed, 23 Apr 2025 21:14:55 GMT

@Woody179!

That's very odd then.

Here's what I get when I click the 3-dots at the bottom of the first message in one of my threads:

abc

Bill

Re: Email could not be delivered

ferguson — Wed, 23 Apr 2025 21:35:35 GMT

I have removed it. I think the edit function for your own posts times out after a certain period of time.