What is TLS?

Transport Layer Security (TLS) is a cryptographic protocol that provides communications security over a computer network. Where 1.2 is its version.

Why are older versions of TLS not recommended?

Older TLS version has security vulnerabilities and is not recommended by Microsoft. They have delayed the deprecation of TLS 1.0 and TLS 1.1 due to covid-19 and is scheduled for October 15 2020. Afterwards, TLS 1.0 and 1.1 support will be removed.

Which version of TLS is supported in Microsoft Office 365?

Microsoft Office 365 recommends TLS 1.2 (or a later version) in order to maintain connection to Office 365 services.

How to make sure that EdbMails uses TLS 1.2 or later version?

Download and install the latest version of EdbMails application from the website. It supports TLS 1.2 or later version and make sure your OS supports TLS 1.2.

Note: Verify EdbMails application version displayed on title bar with the version displayed in the EdbMails website download page.

Is any other verification required?

As EdbMails application does not use the TLS version by itself rather it uses the TLS version that the operating system (OS) supports. Check your system and manually set TLS 1.2 as the default security protocol in your system by modifying the Windows registry (Schannel) if it is required. For more details, please refer to the Microsoft article.

Troubleshooting

Below are the problems that may occur if your environment has TLS 1.2 not enabled or if misconfiguration of TLS exists.

• Connection to Office 365/Exchange Server is not successful. (Please refer the below image)
• Office 365 migration process is not successful.
• IMAP migration is not successful.

  

How to Fix?

• Update the EdbMails software to the latest version from the website.
• Ensure Windows Server and Exchange Server versions support TLS 1.2 since some older versions of Windows TLS 1.2 version are not supported or disabled.

Refer to the below table more details.