Invalid certificate when email checks on Johnny

[biggd]

Greetings all!

 

In the past few days I have noticed an error message stating that the credentials for Johnny are invalid, and now my mail client on my Mac will not allow me to connect.

 

What can be done to correct this?

 

Thanks in advance!

[DmC]

Can you give some more details?

 

Like the exact error you're getting?

[biggd]

Here is the error:

 

"Mail can't verify the identity of the server "johnny.heliohost.org".

 

The interesting thing about this is the error will not allow me to check my my baby.alex mailbox on my Mac Pro (High Sierra)---everything else on the Mac is working properly.