Has anyone seen a Versamail error message while trying to send an email. The error message is <email address> "unbalanced" 535 0.

I composed an email message in the philly airport, and got this message while trying to send.

I then erased the email address, added my email for a test and got the same error.

I then created a new test email with my address and it sent fine.

Then, I tried to create another new message with the original email address, and get the same error. I do not understand what is going in here.

Any ideas?