This document contains instructions on using a non-Microsoft email client, such as Apple Mail or Thunderbird. Microsoft does not recommend these clients for use with Office 365, and there are often significant limitations in client functionality as a result. Because of this, the DoIT Help Desk is only able to offer best effort support for these clients, and certain issues may require the use of a Microsoft client in order to be resolved. For more information on Office 365 client support, please see: Office 365 - Which clients/protocols will be supported?.
Best Effort Support Only
Thunderbird creates a file named persdict.dat where custom dictionary entries are stored. This tutorial will describe how to access this file and its contents.
Exporting Thunderbird Personal DictionaryClose Thunderbird before beginning the following steps.
Click on the Start Menu and enter "%appdata%/Thunderbird/Profiles" (without quotes) in the Search Programs and Files window and hit Enter.
A window should open with the folder containing your Thunderbird profile (the name will likely be different from what's in the picture below). Open the folder.
Inside the folder find the "persdict.dat" file. Copy and Paste it to your Desktop.
Using a text editor (like Notepad), open the "persdict.dat" file saved on your Desktop. You will see your list of custom dictionary words.
In your new email client begin drafting a new message. Copy and Paste your word list from Notepad. Run the spellchecker and add the words to your new email client's custom dictionary.