How did that 1.5GB message get into my Exchange environment anyway?

ISSUE: Recently, I had a customer call in an issue where their transport services were failing on all Exchange 2013 servers usually within minutes of each other. Transport would restart on its own and then 15 minutes to an hour later, they would crash yet again. The following errors were showing up in the Event…

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Mailbox migration times out when going from Exchange OnPrem to O365

ISSUE: When attempting to migrate an onPrem User mailbox from Exchange 2013 to O365, the following error is generated and the migration fails: The request channel timed out while waiting for a reply after 00:00:00.0012345. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time…

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Mail not routing to on-premise Exchange 2013 environment from O365 with 450 4.7.320 Certificate validation failed error

Issue: User is trying to send email from his O365 Tenant in to the OnPrem Exchange 2013 environment. The email fails with the following reason (as seen in the message tracking logs in O365: Reason: [{LED=450 4.7.320 Certificate validation failed};{MSG=SubjectMismatch};{FQDN=hybrid.domain.com};{IP=###.###.###.###};{LRT=4/14/2017 1:07:17 PM}]. OutboundProxyTargetIP: ###.###.###.###. OutboundProxyTargetHostName: hybrid.domain.com Cause: We found that the certificate it was trying…

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