Custom User-Agent string

(This is intended for advanced users only).

In rare cases, an Exchange server may block requests coming from certain types of applications by examining the user agent string sent with requests. In that case, you may be able to resolve the issue by setting a different value for the user agent string used in the http request to the server.

ExQuilla version 24.7 and later provide the ability to set a custom user agent string. This is set by modifying the preference "extensions.exquilla.useragent"  If this value is set to "default" or is blank, then the default user agent string for Thunderbird is used. If set to anything else, that string is used for the user agent for requests by ExQuilla to both autodiscover and EWS servers.

The preference is changed with the Config Editor, which can be reached using the following menu paths:

Windows: Tools/Options/Advanced/General/Config Editor...

OSX: Thunderbird/Preferences/Advanced/General/Config Editor ...

Linux: Edit//Preferences/Advanced/General/Config Editor ...

Note that other addons may also modify the user agent, so the value set there may not be the full user agent that is sent to the server. In particular, if you have Lightning installed it will add its own name and version to the end of the user agent string.