@reub777 wrote:
I contacted them and they said their email address has been blocked by me ? Can anyone help ???
Without knowing the exact error message / Non Delivery Report that the email sender is getting it is just guesswork what is going on. Sadly in these cases most organisations simply push you back to your email provider when in fact it is the sender who has more information about why an email has been blocked.
However, there are a few things you could check:
1) That you have no filter rules set up in your Webmail account and if you do you should disable them temporarily and see if new emails from that sender start coming through. The reason I suggest that is because the webmail filters can have unintended consequences so disabling them rules that out as a possible cause.
2) That your spam settings are NOT set to "Reject all spam messages" because if VM are flagging those emails as spam they will be rejected and a message sent back to the sender. (Possibly that is what they are seeing) Follow steps 1 to 4 below to do that.

3) Finally you could check to see if the domain name of the sender is blacklisted anywhere. Here is the link to one of those blacklist checkers https://mxtoolbox.com/blacklists.aspx Enter the domain name (the part after the @ symbol in the sending address) into the box and click "blacklist check". (So for example if you were checking on emails from the address "info@thiswebsite.co.uk" you would enter "thiswebsite.co.uk"
Post back here how you get on with those suggestions. If they do not yield any obvious issues it would be worth getting in touch with the website again to see if they can give you more precise details of the Non Delivery report they are getting.
Coenoby
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks