Confirmation emails only sending to some

[ollyno1uk2]

It appears that I have had or developed a fault whereby some of my emails that are auto generated are not arriving with the recipient.

 

This includes creating an account, order updates and password forgotten.

 

I personally receive my email confirmations fine to all my accounts. When I test on some other accounts it works fine also. It seems one is Yahoo for sure but also a lot of other domains are as well.

 

I have no idea how to check if I am on a blacklist but 90% of recipients receive the email if I send from the same domain via outlook express so I assume this rules out blacklisting (I would still love to know how to check).

 

I read that others have had similar issues but cannot see a resolution.

 

Thanks a lot in advance.