What is KeepAliveTime used for in regards to Exchange?

This one setting has caused more debates and more confusion, and by proxy, more cases than perhaps any other thing in our Exchange Client Connectivity queues since I started working at Microsoft. There is a lot of confusion on what it is actually used for, so I am going to try and clear that up…

2

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…

2

Owaproxy component is in Inactive State and will not successfully activate

ISSUE: My customer put their Exchange 2016 environment into maintenance mode so they could apply bitlocker to their drives. After applying bitlocker following the guidances outlined in the following article, they were not able to set the ServerComponentState to Active for OWA Proxy: https://blogs.technet.microsoft.com/exchange/2015/10/20/enabling-bitlocker-on-exchange-servers/ The customer runs the following command to see whether the state…

5

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…

1

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…

0

Email destined for recently moved Modern Public Folders are going to the Poison queue.

Scenario I recently worked a case where the customer had moved all of the public folders from one Modern Public Folder mailbox to another and deleted the old Public Folder mailbox. This was on Exchange 2013 CU9. After he did that, email destined for what were previously mail-enabled Public Folders started to show up in the…

0

O365 Migration that completes with warnings due to insufficient rights.

The Problem: With the rise in Hybrid configurations around the world, we are starting to see some regular occurrences of issues around migrating from OnPremises exchange (called OnPrem henceforth) to O365. Perhaps the most common is one where most users migrate fine, but a select few only partially migrate. When you look at the migration logs, they…

0

No properties available on the Exchange Org container in AD Sites and Services

Scenario: So I ran into an odd case this week where the customer could not see the properties of their Exchange Org container in AD Sites and Services. Not only could they not see it, it’s icon, which should have been a folder icon, was actually the notorious Unknown icon. It looked as such: When…

0

Only seeing first receive event when doing message tracking against a public folder that was migrated to O365 from Legacy Exchange

In Exchange 2010 and older (legacy exchange), when you migrate a public folder to O365, it makes a change that causes message tracking to only show the initial receive event when running message tracking against the legacy namespace. Scenario A Public Folder with a Primary SMTP email address of PF1@contoso.com gets migrated to O365. You…

1