Hi Auta, 

I'm sorry to hear you've received a 550 error when trying to send an email. First, try the troubleshooting steps for fixing a 550 error. If the email address is correct and you're still unable to send an email, try contacting them via an alternate method, like by phone or chat. You can also reach out to our live support for additional assistance. I hope this helps! 

Kindest regards,