Did you ever resolve this issue?
I just spent two days on this and my conclusion is that the problem is the discusion between ScrollOut and HMS - it appears that even if you set up a route correctly - and the mailbox definately exists, HMS always sends a 550 when it gets a request from ScrollOut or MailCleaner
HMS does not do SMTP authentication from ScrollOut
I have tried using MailCleaner and get the same error
The route is definately set up to not authenticate from ScrollOuts IP
HMS LOG - from SCROLLOUT
"2016-10-28 13:19:19.802" "196.201.6.67" "SENT: 220 welcome to wine.co.za"
"SMTPD" 4080 50 "2016-10-28 13:19:19.802" "196.201.6.67" "RECEIVED: EHLO scroll.wine.co.za"
"SMTPD" 4080 50 "2016-10-28 13:19:19.802" "196.201.6.67" "SENT: 250-email.wine.co.za[nl]250-SIZE 20000000[nl]250-AUTH LOGIN PLAIN[nl]250 HELP"
"SMTPD" 4040 50 "2016-10-28 13:19:19.802" "196.201.6.67" "RECEIVED: MAIL FROM:<
root@wine.co.za>"
"SMTPD" 4040 50 "2016-10-28 13:19:19.802" "196.201.6.67" "SENT: 250 OK"
"SMTPD" 3660 50 "2016-10-28 13:19:19.802" "196.201.6.67" "RECEIVED: RCPT TO:<
kevin@winenet.co.za>"
"SMTPD" 3660 50 "2016-10-28 13:19:19.802" "196.201.6.67" "SENT: 550 Delivery is not allowed to this address."
"SMTPD" 3660 50 "2016-10-28 13:19:19.818" "196.201.6.67" "RECEIVED: RSET"
"SMTPD" 3660 50 "2016-10-28 13:19:19.818" "196.201.6.67" "SENT: 250 OK"
"SMTPD" 4040 50 "2016-10-28 13:19:19.818" "196.201.6.67" "RECEIVED: QUIT"
HMS LOG from MailCleaner
"41.56.249.156" "SENT: 220 welcome to wine.co.za"
"SMTPD" 2060 385 "2016-10-28 13:32:12.538" "41.56.249.156" "RECEIVED: EHLO welcome to wine.co.za"
"SMTPD" 2060 385 "2016-10-28 13:32:12.538" "41.56.249.156" "SENT: 250-email.wine.co.za[nl]250-SIZE 20000000[nl]250-AUTH LOGIN PLAIN[nl]250 HELP"
"SMTPD" 1576 385 "2016-10-28 13:32:12.585" "41.56.249.156" "RECEIVED: MAIL FROM:<>"
"SMTPD" 1576 385 "2016-10-28 13:32:12.585" "41.56.249.156" "SENT: 250 OK"
"SMTPD" 1352 385 "2016-10-28 13:32:12.632" "41.56.249.156" "RECEIVED: RCPT TO:<
postmaster@southafricanwine.co.za>"
"SMTPD" 1352 385 "2016-10-28 13:32:12.632" "41.56.249.156" "SENT: 550 Delivery is not allowed to this address."
"SMTPD" 2060 385 "2016-10-28 13:32:12.679" "41.56.249.156" "RECEIVED: QUIT"
"SMTPD" 2060 385 "2016-10-28 13:32:12.679" "41.56.249.156" "SENT: 221 goodbye"