SMTP Server Issues using Apple Mail

[Roddy9]

Are any other Apple Mac/iPhone/iPad users having awful trouble sending email. This is the second day and I am really stuck. It started with being unable to send emails to report@phishing.gov.uk, but has worsened to include emails sent to gmail. I have checked mail settings, including ports. The SMTP port was correct (587), but the incoming mail port was 143, which I have changed to 993.
I am repeatedly getting the usual message (below). Can anyone advise please. It affects both my MacBookPro and iPhone 11, both running the latest operating system versions. So frustrating. 

"Sending the message content to the server failed.

The server response was: Reject for policy reason

Select a different outgoing mail server from the list below or click Try Later to leave the message in your Outbox until it can be sent."

[Roddy9]

Grateful thanks Ady.

A little update for you. I did manage to forward 2 emails to the gov.uk phishing mailbox on Saturday, one from my Mac and the other using my iPhone. However, yesterday it was back to square one again on both devices, with the same SMTP failure message. 

I ran Connection Doctor a few times on my Mac yesterday and confirm that all lights were green on each occasion. The problem seems to lie with Talktalk. Let’s hope that your engineers can finally rectify the problem. 

Thanks again for your help. 

[Ady-TalkTalk]

Hi Roddy9, I raised an incident some time ago now for no send issues, but I've heard nothing back since. I'll chase it again and let you know. 

Ady

[Roddy9]

Thanks Ady. 

I am aware of the "dealing with unwanted email" process, but my issue concerns SMTP failure in general (see Message below), which started 2 days ago with trying to report phishing mail to the gov.uk mailbox, then yesterday I was unable to send other unrelated emails to family gmail email addresses (also see message below). I am today able to send successfully to gmail accounts , but am still getting the below message when trying to report phishing to the gov.uk mailbox.

 Is there currently a general ongoing SMTP issue happening please?  If so, I am happy to wait for it to be resolved, otherwise can you please advise me how to rectify my problem. Maybe it is now partly resolved, as there has been an improvement since yesterday?

Btw, I am not very tech literate. I upgraded to a full fibre package a few weeks ago, but can't think that is related to this issue.

Thanks.

The Message that is Displayed when emails are not sent:

"Cannot Send Mail

The connection to the outgoing server

"smtp.talktalk.net" failed. Additional

Outgoing Mail Servers can be configured for Mail accounts in Settings > Apps > Mail > Accounts."

[Ady-TalkTalk]

Hi Roddy9, you can still send the email to TalkTalk if you follow the dealing with unwanted email help article. 

Ady