Emails to me “Undelivered Mail Returned to Sender”

[Montymerlin]

Not getting many emails and as example when buying lottery ticket always get within seconds confirmation of lottery ticket purchase now nothing

just send a mail from another account I have and it was returned with following message 

   5.2.0 Jrl3rAMPqdrTNJrl4rvKxC Content rejected (TT992) (in reply to end of
   DATA command)

so I have no idea which senders are getting this message thus how many emails I am not seeing and thus missing important information

Looking for help or is there a national problem across talk talk?

wife also has same issues

[Gondola]

Try a different email account for testing. If the personal account on iCloud happens not to be authenticated by SPF the standard industry authentication then a TT992 bounce would be expected. There's some reason for the spam protection to be triggered. PM me the domain and I'll check.

As for some senders failing to get mail delivered this is not uncommon. The reason is that your email address is on a suppression list and there's no mail being sent. The reason for mail being on a suppression list is that there will have been an issue getting mail delivered. After retrying and failing delivery then many mail senders will simply cease sending as a self-protection measure against being blacklisted.

Are you forwarding mail to your iCloud personal email? A forwarding fail would cause the delivery failure just as much as a failure of the TalkTalk mailbox.

[Montymerlin]

Thank you for response

Mailbox is not full (as I get some mails, as example notification of your response!) and I have no rules set up, something has happened in last 24 plus hours as I say why do I now not get National Lottery emails when for 10+ years I have, just bought a ticket this morning no acknowledgment again

the personal account I tried which generated the rejection was iCloud so neither hotmail.com or outlook.com

as I say my wife gets on average 20 mails per day but she has had nothing last 18 hours

[Gondola]

If you tested with a hotmail.com or outlook.com email account then the TT992 bounceback is a rejection from TalkTalk's mail servers because of large volumes or spam or not fully authenticated mail sending from the Microsoft servers.

Similar issues were happening with Gmail previously.

So the test is not conclusive of issues with your mailbox.  Have you checked to see if the mailbox is full or if there are Rules diverting mail from the Inbox?