Once the installation and configuration of the add- on is completed , you can add emails in Thunderbird directly to JIRA issue.  

To comment an issue, do the following:

1. Right-click the email you want to create a JIRA issue from.

   By default the body of the email is used as issue description. If you select a part of the email's body text, only the selected text is used as comment.

   At the end of the context menu, you can find the Thunderbird Integration menu items.
   

2. Select Add as JIRA comment from the email's context menu.
   The "Add a JIRA comment" wizard is displayed.
   
   

3. In the first dialog of the " Add a JIRA comment " wizard , you have to specify the issue you want to add the email as comment. To search for the issue, the dialog has five tabs for different search strategies:
   1. Full text: Enter a string that is part of the issue's summary or description.

   2. Issue key: Enter the issue key you want to search for.

   3. Filter favorites: Select a JIRA JQL filter from the pull-down menu.

   4. JQL: Enter a JQL statement to search for issues.

   5. Recent Issues: Search in the list of the recently selected issues
      

      In some cases, you will see an error message in this tab in the bottom right corner. This happens due to errors in the list of recent issues in the Thunderbird configuration. Probably there is an issue in the list, that does not exist (anymore).  To fix the list of recent issues in the Thunderbird configuration, do the following: From the Thunderbird menu, select Edit > Preferences. The "Thunderbird Preferences" dialog appears. Select the Advanced tab. Click Config Editor. A warning message is displayed. Click I'll be careful, I promise! The list of preferences is displayed. Enter jira in the "Search" textbox. You should see the entry "extensions.createjiraissue.lastissues" in the list. Double-click the "extensions.createjiraissue.lastissues" entry. The "Enter string value" dialog is displayed. Check if the listed issue keys exist or if there are double-commas or a single comma at the end of the list of issue keys. Edit the list and click OK. Close the list of preferences dialog. Clock Close to close the "Thunderbird Preferences" dialog.

   In the "Other" tab of the "Thunderbird Integration for JIRA preferences" dialog, you can specify which tab is selected first by default.

   The search results are displayed in the "Search results" frame.
   

4. Select an entry in the "Search results" frame and click Next.
   The second dialog of the "Add a JIRA comment" wizard is displayed.
   
5. The second dialog of the " Add a JIRA comment " wizard displays the following options:
   1. Issue: The selected issue to add the comment to.
   2. Add the email headers: Details see Auto add header information.
   3. Comment: The email body that should be added as comment.
   4. Restrict the visibility of the comment: Select if the comment should be viewable for a single group or all users.

   5. Attachments: Select the email attachments, you want to add to your to your comment.

      A known bug in Thunderbird Integration is that the attachments of the email are not displayed correctly in the Thunderbird Integration user interface. If you need to add an attachment to the JIRA issue it is currently recommended to add it manually after the issue is created. Click Open Issue in the third dialog of the "Add Email as JIRA Comment" wizard (see below). Sometimes you can open the create dialog, choose any project and issue type, wait for the attachments to not appear. Close the dialog and reopen it again, now choosing the desired project and issue type. Chances are good, the attachments have now been downloaded already from the server and are now displayed promptly.

   Enter the additional information and edit – if necessary – the displayed information.
   When done, click Next to create the issue.
   The third dialog of the " Add a JIRA comment " wizard is displayed.
   
6. In the third dialog of the "Add Email as JIRA Comment" wizard you can do the following:
   • Click Open Issue to start your web browser and display the created issue in JIRA.
   • Click Answer Mail to reply on the selected email.
     Defaults for the email subject and body can be defined in the "Reply" tab of the "Thunderbird Integration for JIRA preferences" dialog.
   • Click Open Issue and a nswer Mail to start your web browser (and display the created issue in JIRA) and reply on the selected email.
   • Click Mail settings to display the "Reply" tab of the "Thunderbird Integration for JIRA preferences" dialog.
   • Click Finish to finish the "Add Email as JIRA comment" wizard .