There are webpages which proclaim best this and best that and this one deals with email clients. 

There is no ‘best’. It is all down to whatever suits you. I grew up on Windows Outlook Express, am used to the setup, general feel etc, and am not dumb enough to dislike Microsoft and have to back it up by using a non-Microsoft email client.

So, I use Microsoft Outlook 2010, part of the 2010 Office suite as the main client, and I have lesser accounts running into Windows Live Mail. All are POP3/IMAP capable.

The trouble with..

.. some of the others is that they can be pigs to setup and often introduce elements which can cause email grief BIG TIME. One that springs to mind is INCREDIMAIL.

Incredimail users can have all of the fun that they like at their end, but should should be respectful that most if not all serious mail systems will filter out every last ridiculous effect that Incredimail adds.

For simple email, contacts and Calendar, stick with Microsoft. They work and one of then is FREE, and can be downloaded here..