Unable to send message;Reason:553 Relaying disallowed. Invalid Domain - jason@vividtechnicalservices.co.uk

Unable to send message;Reason:553 Relaying disallowed. Invalid Domain - jason@vividtechnicalservices.co.uk

Since Saturday I haven't been able to send or receive any emails.

I have only just looked in my outbox to find every email I have sent this week sat there unable to send.

As I use this email for my business this is very worrying.

Could you look into this for me please as soon as you can

Many Thanks

Jay