sending mail via crm fails since today

Hi,

since today we have severe problems on sending emails directly via CRM.

We all have our google Mail account connected. None of our five accounts could send mails.
So we had to send the mails from google directly.

As I wanted to make a screenshot right now of the error message, the test email went out...

Anyone had the same issues today? Any solution or explanation?

Thx,

Frank