Outlook

smtp;421 4.3.2 Service not available [outlook.com]

Low severity

smtp;450 4.7.3 Organization queue quota exceeded. [outlook.com]

Medium severity

smtp;451 4.3.2 Temporary server error. Please try again later ATTR17 [outlook.com]

smtp;451 4.4.0 Message failed to be replicated: No healthy secondary server available to accept replica at this time. [outlook.com]

Low severity

smtp;451 4.7.0 Temporary server error. Please try again later. PRX6 NextHop: outlook.com [outlook.com]

Low severity

451 4.7.650 The mail server [x.xx.xx.xx] has been temporarily rate limited due to IP reputation. For e-mail delivery information, see https://postmaster.live.com (S843)[#.prod.protection.outlook.com]

High severity

451 4.7.651 The mail server [x.xx.xx.xx] has been temporarily rate limited due to IP reputation. For e-mail delivery information, see https://postmaster.live.com (S3114) [#.prod.outlook.com #]

High severity

smtp;452 4.3.1 Insufficient system resources (TSTE) [outlook.com]

Low severity

smtp;501 5.1.3 Invalid address [outlook.com]

Low severity

smtp;550 5.5.0 Requested action not taken: mailbox unavailable. [#.eop-nam12.prod.protection.outlook.com]

smtp;550 5.7.1 Service unavailable, MailFrom domain is listed in Spamhaus. To request removal from this list see https://www.spamhaus.org/query/lookup/ (S8002) [#.eop-nam02.prod.protection.outlook.com]

Critical severity

smtp;550 5.7.1 Unfortunately, messages from [x.xx.xx.xx] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [#.eop-nam02.prod.protection.outlook.com]

High severity

smtp;550 5.4.1 All recipient addresses rejected : Access denied [#.eop-nam02.prod.protection.outlook.com]

Medium severity

smtp;554 5.2.122 The recipient has exceeded their limit for the number of messages they can receive per hour. For more information go to http://go.microsoft.com/fwlink/?LinkId=526653. (#) [outlook.com]

smtp;554 5.2.121 The sender has exceeded the limit for the number of messages they can send to this recipient per hour. For more information go to http://go.microsoft.com/fwlink/?LinkId=526653. [#.prod.outlook.com #]