After doing this, if the problem persists then users must try to move from their outdated ExQuilla’s version which does not work properly. To perform this try to do by following steps: Click and download new updated ExQuilla add-on to avoid Thunderbird Failed to Connect to Exchange Server Error; Open your Thunderbird email client; Move to Tools. ExQuilla allows Thunderbird users to read messages and contacts on Microsoft Exchange Server version 2007 and later. It uses the EWS protocol and requires EWS to be enabled on your email server and domain. ExQuilla is a paid addon and requires a paid license. Keeping ExQuilla working with future Thunderbird versions is a lot of work and ongoing. Apr 26, 2013 Thanks to Zendesk's ExQuilla Thunderbird addon, you can connect Thunderbird to your Exchange 2007 or 2010 server through Exchange Web Services (EWS). The setup just requires the installation of an. Thunderbird MS Exchange Mail Server is a worldwide trading community, popular worldwide. An issue that small business owners have to face, without the MS Outlook program, the only option is the webmail of MS Exchange, to overcome this issue, Thunderbird has failed to connect to the Exchange server. ExQuilla is not free, it is licensed on an annual basis. New users are granted a free 60 day trial license automatically. Its also available on the Mozilla Add-ons web site as ExQuilla for Microsoft Exchange. The Exchange EWS provider add-on works with Thunderbird and Lightning.
Exquilla Thunderbird Free
Credits: https://www.techrepublic.com/blog/smb-technologist/connect-the-thunderbird-email-client-to-your-exchange-server/
Install ExQuilla plugin for Thunderbird Using the Add-ons Manager.Alternatively, follow instructions from https://exquilla.zendesk.com/hc/en-us
Restart Thunderbird
Using the web browser, investigate if you can access the Exchange Server. Something like this:https://sync.my.company.com/EWS/Exchange.asmx
If step 3 delivers some WSDL configuration, you are on the money.
On Thunderbird, head to Tools > ExQuilla for Microsoft Exchange
Try to replicate the web address and authentication parameters in order to make Thunderbird retrieve the WSDL configuration.
If everything goes according to plan, Thunderbird will be able to receive and send emails as it would be expected.

Exquilla Thunderbird License
Note: Licenses for ExQuilla are FREE and can be obtained at:http://mesquilla.net/buylicense.html
