Hi,

The email will auto bounce back if I send email and the recipient is point to my contact group. How to solve this issue. The bounce back email is shows below:

Delivery has failed to these recipients or groups:

someone@hotmail.com?
The format of the e-mail address isn't correct. A correct address looks like this: someone@example.com. Please check the recipient's e-mail address and try to resend the message.

Diagnostic information for administrators:

Generating server: 172.18.1.202

someone@hotmail.com?
#550 5.1.3 STOREDRV.Submit; invalid recipient address #SMTP#

Thanks

Hi,

This NDR message indicates that the format of the recipient's address is not incorrect.

I've noticed that there is a question mark behind the email address:

"someone@hotmail.com?
#550 5.1.3 STOREDRV.Submit; invalid recipient address #SMTP#".

Please check whether you have mistakenly added an question mark behind the address, then try again.

Regards,

Ethan Hua
TechNet Community Support