HELP - Can't send e-mail

I've been running eM Cient on my Win 10 laptop for years with no issue.

Today I get the following error message:

smtp server does not support authentication

Here's a screenshot of my error log

Note the line I copied below:

"MailClient.Accounts.SocketException:Connection failed due to the following reason:

An attempt was made to access a socket in a way forbidden by its access permissions 68.87.20.6:25"

Incoming mail comes in OK - HELP