Exchange Server Maintenance Functions

Here’s a couple of PowerShell functions that can be used to put an Exchange 2013/2016 server into “maintenance mode.”

There hasn’t been an official maintenance mode for Exchange Server since Server 2010, which introduced DAG capabilities that greatly improved failover and reduced the need for an official maintenance mode for the servers. With Server 2016, the need for putting a server into maintenance mode has returned due to AutoReseed and AutoDAG features that re-mount databases on their primary server if possible.…

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Resolving Outlook Certificate Errors

How to solve problems with Exchange Autodiscover. Certificate Error issues in particular.

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AC Brown’s IT World is moving

After several years of hosting my website directly on, I’ve decided to migrate to a self-hosted solution instead. This should allow me to implement some new features that are simply too expensive to provide while hosting through In addition, I hope to reduce the number of ads shown on my pages and provide an over-all better experience for admins that use my site regularly.…

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Exchange Server EMail Routing – Accepted Domains and Send Connectors

Exchange Server (And Exchange Online) can be a little confusing at times, particularly when we're dealing with mail routing. Internal mail routes are handled almost automatically (especially if you keep all your Exchange servers in the same AD Site, which I recommend), but how do you get it to route email to mail servers *outside* your organization? This post answers all the questions you might have about how to handle Special Mail Routing cases for Exchange.

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Clearing Logs from All Exchange Servers

IHere’s a fun script. There are plenty of scripts that clear logs from an Exchange server, but this one goes the extra mile by doing it on every Exchange server in your environment (CAS, HUB, and MBX). The short explanation for why is that I work with 16+ node Exchange deployments, so setting up a single-server script on multiple servers is a huge pain.…

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Hardening Microsoft Solutions from Attacks

Take a minute to go over this post from Dirk-jan Mollema. Go ahead and read it. I’ll wait…

Did you realize how scary that kind of attack is? As an IT guy who specializes in Exchange server and loves studying security, that article scared the snot out of me. Based on my experience with organizations of all sizes I can say with a good bit of authority that almost every Exchange organization out there is probably vulnerable to this attack.…

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Enabling Message Encryption in Office 365

As I mentioned in an earlier post, email encryption is a sticky thing. In a perfect world, everyone would have Opportunistic TLS enabled and all mail traffic would be automatically encrypted with STARTTLS encryption, which is a fantastic method of ensuring security of messages “in transit”. But some messages need to be encrypted “at rest” due to security policies or regulations.…

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Data Encryption – How it Works (Part 1)

I’ve decided to start a short series of posts on data encryption, which is becoming an increasingly important subject in IT as government regulations and privacy concerns demand ever increasing levels of privacy and security.

In this series, I’ll try to cover the more confusing concepts in encryption, including the three main types of encryption systems used today; Private Key encryption, Public Key Encryption, and SSL/TLS encryption.…

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