1- Portable Thunderbird. This is a good feature for carrying your entire email account without having a laptop. I can run thunderbird from the pen drive or copy/sync the directory to a machine and use it there. For example I was in the airport and found PCs with a usb connector and so I was able to check my emails. It is easy to backup and even mess around with a copy of the account.

2- I am not sure if outlook provides tagging but this feature can do wonders.

3- Thunderird have thread view, which I am not sure if outlook provide that or not.

I have not used outlook much but I know it has a lot of features like exchange server support which can be a must have for businesses but for some lite/personal use and specially considering the add-ons, it is a great alternative.

Now with Thunderbird 2 and Lightning, You can manage events, send and receive invitations to and from Apple iCal or other calendars that support ics based invitations.

Not forgetting shared calenders with CalDAV.

Sure Outlook has a lot of enterprise features, but at the cost of an Exchange Server!

I find that Outlook has very poor UI design, unstable and too easily targetted by hackers. I get the impression that the more you use M Software the more you are stuck with them and the more you have to pay for products that are always hard to use and seriously flawed.

Outlook users can’t even send rich text emails with the peace of mind that all the recipients not using outlook can read them. Thanks to the silly winmail.dat thingy.

Seems like it took them abt 7 years to deal with this security loophole that affected Outlook 2000 – 2003.

[microsoft.com]

I’m not about to say that all Microsoft products are great but to say Outlook is seriously flawed, suffers from a very poor UI design, and is unstable is going overboard. I’ve used three different version of Office at two different employers and have had nearly NO problems.

Also, people tend to forget that Microsoft Office offers something many other office productivity suites do not; a development platform. For many enterprises, they use Office to automate many of their back-end day-to-day tasks. Office has a very robust API and it gets better with each release. For the company I was with at the time, the enhancement to the API from Office 2000 to 2003 was worth the cost to upgrade. There was a lot of productivity to gain by leveraging the additions to the API.

For all it’s faults it is still the best solution for the majority of enterprises and small businesses alike.

If you are looking for a note taking application to go with thunderbird I suggest you go for evernote of which both free and paid versions are available.