You may not be allowed to. Do you know for sure that your workplace supports or allows this? Do you know of colleagues who manage to do this? In Thunderbird, '''File|New|Existing Mail Account''' and enter the details. You'll need your login and password, and very likely some info about the server and which protocols and ports it uses. Whilst Thunderbird can look up well-known email providers' settings, or make informed guesses, it's less likely to be able to find all these for itself on a private server OTOH, if your business accounts are provided through Gmail or another well-known provider, it may not be any problem at all. In my own case, the providers are Exchange (aka outlook.com) and Gmail, and so are fairly easy to add to Thunderbird.