Email has stopped being delivered to one address

[#1]

I keep getting an email bounced back from an address I've used for years and have never had a problem with until yesterday. I get the following message:

 550 <***@hrs.ru > recipient rejected - domain has no delivery address (DNS MX or A record) I tried another .ru email which went through ok.

I am using outlook 2007 on a windows 7 computer. The email seems to have got through using Yahoo.

Any ideas on how to fix it? BTW please do not use technical language as I won't be able to understand it.

Thanks B

Moderator's note by Dick (Strat): Link edited.

[#2]

Hi @badger49 

A warm welcome to the forums.

This sounds suspiciously similar to an issue seen a few days ago, where a domain's name server had been blacked balled / thought to have been compromised.  Security systems were then inhibiting access to that name resolution service.  I'll poke this one in the same direction and see if its related.

Superuser citation

This topic has been cited by one of the Superusers; the purpose of which is to provide a note for information which might help to focus continued discussion (but might not result in a staff response).

[#3]

Thanks Townman.