Find Reasons & Fixes of Connection To Microsoft Exchange Is Unavailable

When Outlook is connected to an Exchange Server, it displays the status: Connected to Microsoft Exchange. This makes email communication smooth. But in some cases, the Exchange Server is unavailable. And a message is displayed on the computer screen: the connection to Microsoft Exchange is unavailable.

The disadvantage of this error is that you are unable to open the mailbox and send/receive emails. So, if you are getting such type of error, then you should seek out various troubleshooting fixes. Read this article that will explain some effective fixes to resolve this error. Let's start!

error message

Part 1: What's the Symptom of Exchange Connection Unavailable?

The connection to Microsoft exchange is unavailable outlook 2013 is a common error. There can be some reasons that may lead to this Exchange error, like:

Reason 1: Defective Outlook Add-ons

Outlook uses many Add-ons for a variety of functions, including grammar checking and PDF conversions. These add-ons can decrease Outlook's performance. And they interfere with its connection to the Exchange Server because they come from outside sources.

Reason 2: Exchange Server is not responding

Even though the Exchange Server may have been down when you faced the error in Outlook, you can still wait for it to start working again.

Reason 3: Problem with Third-party applications

Many third-party applications can check other programs and prevent them from operating. Your computer's anti-malware software may sometimes stop Outlook from functioning.

Part 2: How to Fix Microsoft Exchange Is Unavailable?

Now you know why this problem of the connection to Microsoft exchange is unavailable outlook 2016 happens. It's time to know how you can fix this error. In this part, I will explain 9 effective fixes that would help you to resolve this error and make email communication smoother.

Let's dive into the method.

#Fix 1: Disable the encryption requirement on all CAS servers

This fix is only for IT administrators who can turn off the encryption requirements. Microsoft advises against using it unless necessary. This is because you may not be able to immediately deploy the required RPC encryption settings on your Outlook clients. To disable the encryption requirement on all CAS, Enter the following command into the Exchange Management Shell:

exchange management shell

All Client Access servers running Exchange Server 2010 or a later version require the execution of this cmdlet. Run this command again for each Exchange server that has the Client Access Server role. Also, as mentioned in the preceding step, disable RPC encryption. But after deployment with changes to the RPC requirement in Outlook, make sure to re-enable it.

#Fix 2: Delete and Create a New Outlook Profile

If your Outlook profile's settings are the cause of the "Microsoft Exchange is unavailable" issue, this method is the best.

First, I will let you know the steps by which you can delete your existing Outlook profile.

Step 1: Open Outlook.

Then, select the info and Account settings dropdown. Next, go to Manage Profiles.

account settings

Step 2: The Mail Setup window will appear.

Select Show Profiles from the menu.

mail setup window

Step 3: You can remove the default profile by selecting the Remove button.

choose remove

Step 4: Restart Outlook.

To create a new profile, simply follow the onscreen instructions and enter the required credentials. Once your new Outlook profile has been created, check to see if Outlook the connection to Microsoft exchange is unavailable in Outlook 2013.

The instructions are as follows:

Instruction 1: Go to the Control Panel.

control panel

Instruction 2: Locate and select the Mail item in the Control Panel.

control panel items

Instruction 3: Select "Add..."

select add

Instruction 4: In the Profile Name field, enter a name for the new profile.

new profile

Instruction 5: Provide any additional credentials required. And, then follow the onscreen instructions to create the new profile.

Instruction 6: Once the new profile has been created, make it the default profile for Outlook. You can check the Always use this profile box and open the dropdown menu directly beneath it. And, then select the newly created profile.

mail window

#Fix 3: Update or create your Outlook profile with RPC encryption

The communication channel between an Outlook client computer and an Exchange server via RPC is not encrypted. A malicious person may be able to access confidential information if they can spy on network traffic between Outlook and the server.

To update or create your Outlook profile with RPC encryption, here are the steps:

Step 1: Launch Outlook, then select Account Settings, then Manage Profile.

choose manage profiles

Step 2: Click on Email accounts to access the emails set up with the Exchange server.

mail setup

Step 3: Click on Change and More Settings after that.

change account

Step 4: In the Microsoft Exchange window, go to Security tab.

Then, mark the checkbox of Encrypt data between Microsoft Outlook and Microsoft Exchange.

microsoft exchange window

#Fix 4: Flush your computer's DNS

The connection to Microsoft exchange is unavailable outlook 2010 problem may also happen due to an issue with your computer's DNS. Fortunately, the DNS on a Windows computer can be easily flushed. To clear your computer's DNS, do the following:

Step 1: Launch the Start Menu.

Step 2: Look up "cmd."

Step 3: To launch an elevated Cmd with administrative privileges, right-click on the search result titled CMD. And, select Run as administrator.

open cmd

Step 4: Enter the following commands into the elevated Command Prompt:


enter the command

Step 5: Close the elevated Command Prompt.

Step 6: Check to see if the issue has been resolved.

#Fix 5: Start the Microsoft Exchange system attendant service on your Microsoft Exchange server

It is not compulsory that the error connection to Microsoft exchange is unavailable outlook 2016 always happens from client-side. However, sometimes the cause of the issue lies on the server. The M.E.S Attendant service not running on the Microsoft Exchange server is the most common server-side cause of this problem. In such cases, despite being configured to start automatically, the M.E.S Attendant does not run on the Microsoft Exchange server.

So, to start this service on your Microsoft Exchange server, follow the steps mentioned below:

Step 1: Enter Windows Powershell and Run as Administrator in the search box.

Step 2: In the details pane of the Services window, find the Microsoft Exchange System Attendant service.

Step 3: Click Start by using the service's right-click menu.

Stop and restart it if it has already begun.

#Fix 6: Start Creating new alias for the Office 365 user

If you still get the error message - the connection to Microsoft exchange is unavailable outlook 2016, you need to start creating new alias for the Office 365 user.

So you can do this task by following the steps:

Step 1: Log into the Exchange administration center.

Step 2: Choose Recipients.

choose recipients

Step 3: Choose Mailboxes.

choose mailboxes

Step 4: Click the user's mailbox twice.

user mailbox

Step 5: Choose Email address. Then, press (+).

email address

Step 6: Choose SMTP.

Step 7: Now, include a new alias.

Use the alias you just created to set up Outlook instead of the user's email address. When prompted to enter credentials during the Outlook setup process, enter the user's actual Office 365 email address.

new email address

#Fix 7: Run Microsoft Support and recovery assistant

If you are receiving the error of connection to Microsoft Exchange is unavailable in Outlook 2013, you may be able to resolve this issue by downloading the Microsoft Office 356 Support & Recovery Assistant tool. After downloading this tool, run it and allow it to resolve any potential issues.

A few users reported that this tool resolved the Microsoft Exchange error message on their computer, so you might want to give it a shot.

#Fix 8: Change the user name or password

This is a simple solution to the "connection to Microsoft exchange is unavailable outlook 2010" issue. It involves changing the user name or password of the user's Office 365 so that it is unique for the user's Office 365 account.

#Fix 9: Deploy a Group Policy setting to update existing Outlook profiles with RPC encryption

Group Policy can also be used to modify RPC settings on the server. First, open the Run Command window by pressing Windows + R, then type gpedit.msc and press Enter to launch the Group Policy Editor.

Navigate to the following address.

Account Settings > Exchange > User Configuration > Administrative Templates > Microsoft Office "Version number"

Locate and disable Policy Enable RPC Encryption.

Bonus: How to Fix Unaccessible Emails in Outlook?

You have now learned how to fix Microsoft Exchange is unavailable. What would you do if your emails were inaccessible in Outlook? Do you know? If not, I will let you know in this part.

If your Outlook emails are not accessible, you can use the best email repair program tool, Wondershare Repairit for Email. Repairit for Email is a one-stop solution for Outlook email repair. It can recover emails that have been deleted or damaged.

Let's get into its features.

  • Repair damaged PST & OST Files in Outlook in all Email corruption scenarios, such as hard disk crashes & bad sectors, virus attacks & tojan horse, outlook corruption & malfunctions, improper shutdown procedure, etc.

  • Restore Outlook Emails deleted for a long time and extract the Email messages, folders, calendars, etc. within seconds.

  • Repair corrupted Emails and restore deleted Emails with a very high success rate.

  • Repair Emails in bathes without size limits and support to preview all of them before saving.

  • Compatible with Windows 7/8/8.1/10/11, Windows Server 2012/2016/2019, and MacOS X 10.11~ MacOS 12 (Monterey).


With the help of the fixes mentioned above, you can easily resolve the error the connection to Microsoft Exchange is unavailable. Moreover, use Wondershare Repairit for Email to repair your corrupted files by following easy steps.