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Hotmail and Outlook Email Error Code List

Category: Getting Started
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Mail servers utilizing SMTP have a pre-defined errors that correspond with an identifier that provides an explanation as to why the sending mailer received a bounceback. These bounceback messages/error codes are default in mail servers but every provider may be different in how/what they address those errors as.

Provided below is a composed listing of known Microsoft Hotmail/Outlook error codes that one may receive as a bounceback.

https://sender.office.com/

SMTP Error Code Explanation (Click to Expand)

421 RP-001

The mail server IP connecting to Outlook.com server has exceeded the rate limit allowed. Reason for rate limitation is related to IP/domain reputation. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

421 RP-002

The mail server IP connecting to Outlook.com server has exceeded the rate limit allowed on this connection. Reason for rate limitation is related to IP/domain reputation. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

421 RP-003

The mail server IP connecting to Outlook.com server has exceeded the connection limit allowed. Reason for limitation is related to IP/domain reputation. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

550 SC-001

Mail rejected by Outlook.com for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

550 SC-002

Mail rejected by Outlook.com for policy reasons. The mail server IP connecting to Outlook.com has exhibited namespace mining behavior. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

550 SC-003

Mail rejected by Outlook.com for policy reasons. Your IP address appears to be an open proxy/relay. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

550 SC-004

Mail rejected by Outlook.com for policy reasons. A block has been placed against your IP address because we have received complaints concerning mail coming from that IP address. We recommend enrolling in our Junk Email Reporting Program (JMRP), a free program intended to help senders remove unwanted recipients from their email list. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

550 DY-001

Mail rejected by Outlook.com for policy reasons. We generally do not accept email from dynamic IP’s as they are not typically used to deliver unauthenticated SMTP email to an Internet mail server. If you are not an email/network admin please contact your Email/Internet Service Provider for help.¬†http://www.spamhaus.org¬†maintains lists of dynamic and residential IP addresses.

550 DY-002

Mail rejected by Outlook.com for policy reasons. The likely cause is a compromised or virus infected server/personal computer. If you are not an email/network admin please contact your Email/Internet Service Provider for help.

550 OU-001

Mail rejected by Outlook.com for policy reasons. If you are not an email/network admin please contact your Email/Internet Service Provider for help. For more information about this block and to request removal please go to: http://www.spamhaus.org.

550 OU-002

Mail rejected by Outlook.com for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation. If you are not an email/network admin please contact your Email/Internet Service Provider for help.