hi Ray Yang,
the email never leaves the faxe, so after asking for help at the faxes sopport they answered this:
The error you are receiving 'Email address not recognized' is caused by a feature of the email address you are using called "Bounce Address Tag Validation". This feature is not supported by our new servers and you will need to contact the provider of your email address to have that feature turned off, if possible. If it is not possible to turn this feature off then you will need to use another email address like a Gmail, Yahoo or Hotmail address to send faxes as these email accounts do not use this feature. For more information on the "Bounce Address Tag Validation" feature you can read this Wikipedia article en.wikipedia.org/.../Bounce_Address_Tag_Validation . Unfortunately, this is not an issue we can correct you need to speak with your email provider.
so that is why i need to know if there is a way to turn off the “Bounce Address Tag Validation