This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: kathryn@fabians.co.za host fabians-co-za.mail.protection.outlook.com [104.47.9.36] SMTP error from remote mail server after RCPT TO:: 550 5.7.51 TenantInboundAttribution; There is a partner connector configured that matched the message's recipient domain. The connector had either the RestrictDomainsToIPAddresses or RestrictDomainsToCertificate set [VE1EUR03FT064.eop-EUR03.prod.protection.outlook.com] kathy@bryson.co.za host mx1.mweb.net [196.35.198.130] SMTP error from remote mail server after RCPT TO:: 550-rejected because 13.251.245.207 is in a black list at combined.abusix.dnsbl 550 https://lookup.abusix.com/search?q=13.251.245.207 kathryns@tshwane.gov.za host securemail-mx1.synaq.com [196.35.198.158] SMTP error from remote mail server after RCPT TO:: 550-rejected because 13.251.245.207 is in a black list at combined.abusix.dnsbl 550 https://lookup.abusix.com/search?q=13.251.245.207 kathy@brabys.co.za host guardian.brabys.co.za [196.216.215.59] SMTP error from remote mail server after RCPT TO:: 550 5.1.1 : Recipient address rejected: User unknown in virtual mailbox table kathrinemack@mweb.co.za host securemail-mx3.synaq.com [196.35.198.130] SMTP error from remote mail server after RCPT TO:: 550-rejected because 13.251.245.207 is in a black list at combined.abusix.dnsbl 550 https://lookup.abusix.com/search?q=13.251.245.207 kathryng@thomas.co.za host thomas-co-za.mail.protection.outlook.com [104.47.4.36] SMTP error from remote mail server after RCPT TO:: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) [AM5EUR02FT031.eop-EUR02.prod.protection.outlook.com] kathryn.h@permark.co.za host mail.permark.co.za [41.169.97.44] SMTP error from remote mail server after RCPT TO:: 550 , Recipient unknown kathryns@ridge.gp.school.za host mopani.school.za [197.157.95.68] SMTP error from remote mail server after RCPT TO:: 554 5.7.1 : Relay access denied kathrinh@ridge.gp.school.za host mopani.school.za [197.157.95.68] SMTP error from remote mail server after RCPT TO:: 554 5.7.1 : Relay access denied kathrine.starke@added-value.co.za host mxa-00174f01.gslb.pphosted.com [67.231.148.206] SMTP error from remote mail server after pipelined DATA: 550 5.1.1 User Unknown