Hello, We are using Dnsbl.sorbs.net as our real-time block list (RBL) on our Edges. I did a Get-AgentLog on the recipient got the below result: Action : RejectCommand SmtpResponse : 550 5.7.1 External client with IP address 127.1.0.1 does not have permissions to submit to this server. Visit http://support.microsoft.com/kb/928123 for more information. In fact some addresses from our client goes are accepted and some other not I did check on a website and the IP is blacklisted (see below) My question or the advice I would like to get from you is What is the best thing to do and what risk would I take. For instantce: - I could whitelist the domain but correct me if I am wrong but I would leave a open door in my company - I could add the IP address but I am not sure if it is safe - I could get back to our client and tell him to get in touch with http://www.us.sorbs.net/cgi-bin/support to get their IPs removed from sorbs Could you please advice me?? Thanks The IP address 127.1.0.1 is blacklisted. RBLs checked: Spam Haus not listed Spam Cop not listed Mailwall-Reject RBL not listed Barracuda not listed Abuse At not listed SORBS not listed SORBS Spam listed : Escalated Listing (Spam or Spam Support) See: http://www.sorbs.net/lookup.shtml?127.1.0.1 NJABL not listed 510 SG listed : RATS-Spam not listed Lashback listed : http://www.lashback.com/support/UBLLookup.aspx?IP=127.1.0.1 UCEPROTECTL1 not listed UCEPROTECTL2 not listed UCEPROTECTL3 not listed NIXSPAM not listed PSBL not listed MimeCast listed : Message filtered due to security policies. For more details please see

Hi, The best bet is to whitelist the ip.... if you trust the domain owner. As far as other anti-spam results are concerned they are going to be conducted on the mails. Thanks.