What is the Thunderbird app?

Related questions

1. Does Thunderbird work with Outlook?
2. How do I import mail into Thunderbird?
3. Does Mozilla Thunderbird work with Gmail?
4. Does Thunderbird have an Android app?
5. Is there Thunderbird for Android?
6. Can I sync Thunderbird calendar with iPhone?
7. Where does Thunderbird store passwords?
8. Is there a 64 bit version of Thunderbird?
9. Can Thunderbird be used with Gmail?
10. Can I get Thunderbird on my iPhone?

Tags

1. #ubuntu
2. #after
3. #systems
4. #source
5. #installed
6. #email
7. #default
8. #thunderbird
9. #browser
10. #cross
11. #client
12. #mozilla
13. #platform
14. #firefox
15. #desktop
16. #foundation
17. #modeled
18. #project
19. #developed
20. #strategy