Microsoft KB Archive Search

Notice: This website is an unofficial Microsoft Knowledge Base (hereinafter KB) archive and is intended to provide a reliable access to deleted content from Microsoft KB. All KB articles are owned by Microsoft Corporation. Read full disclaimer for more details.

  1. Home
  2. Products
  3. Exchange Online Protection

Articles for product: Exchange Online Protection

Article ID Article Title Hidden
954199 Description of the policy for how e-mail is filtered by the junk e-mail filters in Outlook or in Exchange Server
2604282 The Junk Email Reporting Add-in doesn't appear in Outlook
2750145 Email messages sent from Office 365 users in a hybrid deployment are rejected, and nondelivery reports are received
2823261 Changes to a data loss prevention policy don't take effect in Outlook 2013 in Office 365
2823263 How to troubleshoot data loss prevention policy tips in Exchange Online Protection in Office 365
2827473 "550 5.4.1 Relay Access Denied" NDR when sending mail from an on-premises Exchange organization through Exchange Online Protection in Office 365 Dedicated/ITAR
2845046 Users in an Exchange Online Protection environment receive NDRs when they send mail to a recipient environment that uses the China Anti-Spam Alliance service
2909418 Mac users can't release messages from Exchange Online Protection quarantine
2959596 How to reduce malware threats through file attachment blocking in Exchange Online Protection
2989744 In-Place eDiscovery preview is not available for items in inactive Exchange Online mailboxes
2998901 "SMTPSENT.BareLineFeedsAreIllegal" NDR received by Exchange Online or EOP users in Office 365 Dedicated/ITAR
3003043 "The rule can't be created because it is too large" error when you try to create or change a transport rule
3013740 Sender receives a "5.7.1 Unable to Relay: Blocked by Customer Allow List" NDR error message
3019655 Recipient rejects mail from Exchange Online or Exchange Online Protection, and you receive a "host name does not match the IP address" error
3019657 Domains on the Outlook Safe Senders list aren't recognized by Exchange Online or Exchange Online Protection
3024906 "550 5.7.1 Message rejected due to content restrictions" when you send email to external recipients in Exchange Online Protection
3079142 Email messages are incorrectly quarantined in Exchange hybrid deployments that use centralized mail control
3089691 Lots of false positives are generated when the "SPF record: hard fail" advanced spam filtering option is enabled
3145666 "550-DKIM" NDR error when Office 365 users send mail to an external domain
3179588 "The domain of the recipient is not configured as part of connector" error when you validate a connector in the Exchange admin center in Office 365
3194415 Some messages aren't routed through the on-premises organization when you use centralized mail transport
4052852 Mail can't bypass spam filtering when the sender's IP is added to the Client Allow List
4492048 "550 5.6.0 APPROVAL.InvalidExpiry;Cannot read expiry policy" when sending a message to a moderated distribution group
4498191 "Tenant has exceeded threshold" NDR when mail is sent from your organization