Monday , October 5 2020


535 Authentication Credentials invalid on Outgoing mails

Suddenly Outgoing mails stopped. with below error Error : Exchange Toolbox – queue Viewer 4.4.0 Primary Target IP Address Responded with: “535 Authentication Credentials invalid.” Attempted to failover to alternate host, but that did not succeed. Either There are no Alternate hosts, or delivery failed to all alternative hosts. Solution …

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550 Address unknown – Sophos UTM 9

From Office365/Gmail fails to Exchange On-Premises External to Internal Mails 550 Address unknown Anti-spam Sophos UTM 9 NDR From Office 365 to Exchange 2010/2013/2016 On Premises – Original Message Details Created Date:11/8/2016 4:25:50 PMSender Address:test@external.comRecipient Address:user@careexchange.inSubject:Test333   Created Date: 11/8/2016 4:25:50 PM Sender Address: Recipient Address: Subject: Test333 …

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