For three months, I have been using Xobni, a free plug-in for Microsoft Outlook which removes a lot of the pain of using this widely-used but widely-unpopular application.

If you have trouble remembering the product’s name, it’s ‘inbox’ backwards. It works by indexing all your emails, not just those in your inbox. This gives you instant recall of emails by sender/recipient or by content.

Last week, after seven months of pre-beta trials, the product was launched to the public. I sent out several invites to use it to friends and they are all rather smitten.

When not in use, it sits quietly in a narrow sidebar in your Outlook, showing details of the sender or recipient of the current email. Without expanding the bar, you can see the size of their network (derived from cc’s and such), how many conversations you’ve had with them and how many files you’ve exchanged. Expand the bar and you can see their telephone number and scrollable lists of the items just mentioned.

Here’s a shrunken screen shot with the sidebar showing:

And here’s the sidebar expanded (I’ve deliberately shaded my phone number):

You can call people from Skype, email them or schedule time with them, all from inside Xobni. You can also see a pattern of when they’re most active, email-wise. This is borne out of the company’s original intention to be an email analytics firm.

If you use search, then you get back matching people and emails. Click on an email and you can reply, forward or open. You can also view the conversation and this has a dinky slider which enables you to see more, or less, of each email in the list.

Like so many programs, it is easier to just have a go than to have someone try to explain it in print. I have ten invites to send out, if anyone’s interested (send me your email address). But it’s just as easy to go to the Xobni site and pick up your own free copy.

Xobni runs on Microsoft Windows XP or Microsoft Vista with Outlook 2003 or 2007. Once installed, you do nothing. It is automatically updated when the program is improved.

If you’re anything like me, you mostly use the powerful search to find stuff that you know is in there somewhere. The rest is icing on an already tasty cake.