Cannot reply on email?

Hi!

Few days I have the same problem - I cannot reply to anyone's e-mail!
All the time I got the same warning that my smtp outgoing server is not good. But I checked it few times - everything is ok!
And I can compose new e-mail (with any adress) and everything is working fine!

Can you help me with this?
I tried to find some preferences just for Reply e-mail, but I couldn't find it..

Thanx!
McMaki

 

Thanks for your reply.

I already checked it - everything is ok with information. And with all that information everything worked fine last half a year till few days ago.

We had some migration of domains, we got new ones, but all that changes I made few months ago, while they still goes parallel..