Modules — Required

1. Organic Groups 6.x.2.x-dev
2. Messaging 6.x.4.x-dev (If you are not already using this version it might be better to use Messaging 6.x-2.x-dev)
3. Notifications 6.x.4.x-dev (If you are not already using this version it might be better to use Notifications 6.x-2.x-dev)
4. Mailhandler 6.x.2.x-dev
5. Mailcomment 6.x.2.0
6. Feeds 6.x.1.0-beta 11
7. PHPMailer 6.x.3.1
8. Feeds Comment Processor 6.x.1.0-beta1 — required by other modules
9. Chaos Tools 6.x.1.8 — required by other modules
10. Libraries 6.x.1.0 — required by other modules
11. Token 6.x.1.16 — required by other modules

Modules — Adding bells & whistles

1. Action Email Role 6.x.1.11
2. HTMLMail 6.x.1.7
3. Multiple Email Addresses 6.x.1.3
4. Comment Upload
5. FileField 6.x.3.0
6. ImageField 6.x.3.0
7. FileField Sources 6.x.1.4
8. Private Upload 6.x.1.x-dev
9. Private Download 6.x.1.3
10. FileField Paths 6.x.1.4
11. Relative to Absolute Filter 6.x.1.1 — required by other modules
12. MailMIME 6.x.2.15 — required by other modules
13. Notifications Team UI 6.x.2.1-beta 8
14. MIME Router 6.x.1.0 — required by other modules
15. MIME Detect 6.x.1.3 — required by other modules
16. Transliteration 6.x.3.0 — required by other modules
17. Autoload 6.x.2.1 — required by other modules
18. Job Scheduler 6.x.1.0-beta 3— required by other modules

This list is up to date as of Dec. 10, 2011.