Outlook Client - Stuck on Trying to Connect

  • A few weeks ago, I started getting reports of users where Outlook got stuck on trying to connect. This was after it was working fine. They would notice that they hadn't received any emails and that they would have messages stuck in the outbox.

    This is happening on Windows 7 Pro x64 and Windows 10 Enterprise x64. With the most recent builds of Office in both 32bit and 64bit versions.

    The temporary fix is usually a reboot. Sometimes, I have to remove and create a new mail profile. This is also only temporary.

    I finally opened a ticket with Microsoft support. They had me download a tool at https://diagnostics.office.com/#/ and run it on the affected system. It goes through some checks for logging in, so it requires the user to login to office 365 via the tool. The first error I got was related to TLS 1.2 not being enabled. However, I have a GPO that is applied to the system with the following settings:


    After moving to the next step in the tool, it suggested removing the stored credentials (something I had done in previous cases without result). This time was no exception, as it didn't fix it. I moved to the next option, which was to have the tool delete and recreate the profile. The tool prompted to login to O365 and just sat there for several minutes. I force quit it and rebooted the system. Once it came back up, we started Outlook, it prompted to use the new profile and we logged into O365 and it finally came back showing connected.

    I spoke with support while creating this post. He said I should make sure that TLS 1.0 is disabled on the system but couldn't tell me why that would be showing if the GPO was applying. According to GPR run against the system, it is applying the setting mentioned above. There was also a Windows update (KB 3140245), but that was already installed. Also, if TLS were truly the cause, Windows 10 should not be affected, as 1.2 should be the default TLS version.

    Who else is seeing this issue and have you managed to resolve it permanently?

  • I have a laptop that isn't kicking back that TLS error in that Office tool. I have tried moving another system that does get the TLS error into the same OU as the laptop and ran gpupdate /force and rebooted, also brought Windows fully current and uninstalled Webroot. Can't figure out the difference