There are a number of solutions available that can resolve the issue related to Microsoft Outlook and Exchange server connectivity. Techniques to Remove Error ‘Microsoft Exchange Server is Unavailable’
Read this post to find out more on how to remove this error and restart the communication process. This causes the server to be unavailable for communication. The root cause behind this issue is that Outlook keeps disconnecting from Exchange server. Accessing the copies of mailbox data saved on Exchange server becomes difficult.
These errors prevent users from sending and receiving their emails. One such error message is Microsoft Exchange Server is unavailable. These error messages are nothing but indications that something is wrong with the way Outlook is communicating. There is the number of times when Microsoft Outlook starts generating error messages.
Attempt to apply cumulative update database update.
Digitally signing Adobe Acrobat PDF documents with.Fixing the “We didn’t find an audio device, which.Now when you telnet to the Exchange server, you should see the 250-STARTTLS option: Note that I already had a certificate assigned so was prompted to overwrite the existing certificate. I find most administrators tend to miss step 2 which is to assign a certificate to the SMTP service so ensure that you have a certificate with the CN or an entry in the SAN that matches the MX to A record name, then use the:Ĭopy the Thumbprint and then execute the following cmdlet:Įnable-ExchangeCertificate -thumbprint -services:SMTP Step #2 – Assign a certificate to the SMTP service: If you open up the properties of the receive connector, you’ll see that the Enable Domain Security (Mutual Auth TLS) setting is checked off: Note how the screenshot above now displays the DomainSecureEnabled property as being True. Set-ReceiveConnector -DomainSecureEnabled $true -AuthMechanism TLS Get-ReceiveConnector | FL DomainSecuredEnabled ... and scroll to the DomainSecureEnabled setting: You can also check to see if the setting is enabled by using the: The second way of enabling the setting is to launch PowerShell then use the Set-ReceiveConnector cmdlet. Open up the properties of the receive connector and navigate to the Authentication tab, then check off Enable Domain Security (Mutual Auth TLS): To enable the setting in the EMC, navigate to Microsoft Exchange On-Premises –> Server Configuration –> Hub Transport and select the appropriate receive connector that receives email from the internet: … are actually the same as one of them is configured through the Exchange Management Console and the other is through PowerShell. Enable Domain Security (Mutual Auth TLS).Step #1 – Turn on “Enable Domain Security (Mutual Auth TLS)” or enable “DomainSecuredEnable” setting: Notice how the screenshot above does not contain the 250-STARTTLS output which means this Exchange server is not going to accept TLS connections. … and look for 250-STARTTLS in the output: **Note that I’m logged directly on the Exchange server in the screenshot above so please substitute localhost with either the external MX record or the name / IP of the hub transport server if you’re coming from the internal network. The easiest way to determine whether the Exchange server is performing opportunistic TLS is to simply telnet to the hub transport server via port 25: How do you know whether your Exchange server is performing opportunistic TLS? What I’ve found was that most administrators tend to perform only 1 of 2 steps and therefore left wondering why TLS isn’t offered by the Exchange server so this post serves to outline the steps so that I can direct anyone who runs into this issue to this blog post. I’ve recently been asked to troubleshoot why TLS wasn’t working for an Exchange 2010 server even though the obvious settings have been configured.