SyncKolab can synchronize your calendar, address book and tasks against an IMAP server in Kolab formats version 1 (vCard/iCal) or version 2 (XML) or turn your Thunderbird/Lightning into a native Kolab Client (http://kolab.org).
Highlight multiple emails, right-click, then select "One-by-One Forward". This extension will allow you to forward the selected emails, one-by-one, to the recipients you specify using your choice of attachment handling.
Create Jira Tickets directly from within Mozilla Thunderbird (based on E-Mails). This Addons saves your Username and Password in clear text. Use on your own risk. (Also, you might need to disable the CSRF Filter in your JIRA Instance.)