Email issue: When sending a mail, this is returned to me :

Hello everyone, thanks in advance for your help.

I suddenly start having the following problem. When sending a mail, it never get to destiny and it is returned to me saying this:

"TLS Negotiation failed, the certificate doesn't match the host"

I've change port number in my settings and change options from TSL conection to "No secure connection" (just to try a solution) and seems to work, but it appears in Spam's folder recipient and outlook clients have not even received the mail.

How can I set it, to make it work well. Thank you!! (sorry for my english)

Carolina