unable to send or receive email from Comcast email address

I recently signed up for Comcast and had to create a new email address using the free Comcast business portal. However I am unable to send emails, ie never delivered. also when someone tries to email me they get; Delivery has failed to these recipients or groups: service@garrettautomotive.biz A problem occurred and this message couldn't be delivered. Check to be sure the email address is correct. If the problem continues, please contact your helpdesk. Diagnostic information for administrators: Generating server: copdcmhout02.cable.comcast.com service@garrettautomotive.biz Remote Server returned '< #5.4.4 smtp; 554 5.4.4 [internal] Domain Lookup Failed>' Original message headers: X-AuditID: 60729ed4-f79ad6d000000ef9-9d-56feb19e190d Received: from COPDCEX16.cable.comcast.com (Unknown_Domain [96.114.156.147]) (using TLS with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by copdcmhout02.cable.comcast.com (SMTP Gateway) with SMTP id BB.06.03833.E91BEF65; Fri, 1 Apr 2016 11:36:30 -0600 (MDT) Received: from COPDCEX13.cable.comcast.com (147.191.124.144) by COPDCEX16.cable.comcast.com (147.191.124.147) with Microsoft SMTP Server (TLS) id 15.0.1130.7; Fri, 1 Apr 2016 11:36:29 -0600 Received: from COPDCEX13.cable.comcast.com ([fe80::3aea:a7ff:fe36:8354]) by COPDCEX13.cable.comcast.com