If your still using Exchange 2010 then you need to upgrade fast as the end of support for Microsoft Exchange Server 2010 was extended from January 14th 2020 to October 13th 2020 to give customers more time to complete their migrations.
This extension also aligns with the end of support for Office 2010 and SharePoint Server 2010.
After October 13th 2020, Microsoft will no longer provide technical support for Exchange Server 2010, including bug fixes, security fixes, and time zone updates. Your installation of Exchange 2010 will continue to run after this date. However, we recommend upgrading to Exchange Server 2013 or ideally 2016 to remain secure and supported.
Microsoft Exchange 2010 support roadmap – https://docs.microsoft.com/en-gb/lifecycle/products/exchange-server-2010