Mail is working from Google/gmail and several other providers. Everything also looks ok using diagnostics like mxtoolbox.com. Please check with your email provider to see if they can provide more detail on what they consider to be invalid in this case.
- Wukix, 1034 days ago
I was trying to send an email from my email account that is registered here. Now I managed to send it again from my Gmail account so I am closing this ticket.