Exchange server uses three "get mail" protocols. IMAP, POP and EAS.

The product ships from Microsoft with IMAP and POP both turned off as well smtp for sending mail, simply because Microsoft want you to buy Outlook which interact with exchange over EAS.

It is a trivial setting in exchange server to enable IMAP, POP and SMTP. Unfortunately most places Exchange is installed do not have a technician experienced in any technologies other than "Microsoft" so they are reluctant to use non standard Microsoft settings.

Alternatively you can buy the Exquilla add-on for Thunderbird https://addons.mozilla.org/en-US/thunderbird/addon/exquilla-exchange-web-services/ but your already paying extra for exchange from your provider.(Hosting packages with exchange as almost universally more expensive that those that offer collaboration services)

Thanks for the answers. Sounds complicated and I can't get the hosting company to change their ways so I decided to switch to Outlook.

jeanpierredemontigny, you should change your hosting company. At the moment you are paying them to make you pay for Microsoft Outlook.

Would you pay money to a new postal service to install an additional letterbox on your front door that only they could use? That is an analogous situation.

And no, it shouldn't be complicated. If your email provider did what they are supposed to do and provide standard email interfaces, then basically all you should have to do in Thunderbird is type in your email address and password.