This is a topic of much confusion.
I did not find any article on developerworks/Infocenter that clearly talks about the various options, So I will make an attempt to clear it up a little bit.
In WPS 5.1 , there are three ways to bring in collaboration
a) LotusNotes View Portlet
b) Domino Web Access (iNotes)
c) Common Mail Portlet (Part of the PIM Personal Information Management Portlets)
Assuming you have confgiured everything else correctly*, Let us look at each one separately. Lotus Notes View Portlet
This is probably one of the earlier and easiest method of setting up a mail portlet. The two cool things about this portlet is that it supports People Awareness and 'Launch in Lotus Notes' option. This portlet also respects the theme settings of the portal to some extent. But this is a very basic mail porltet and does not allow access to mail folders (other than InBox) by default.You can setup mail , Calendar or ToDo by just changing the PropertyType of the portlet.Domino Web Access (iNotes)
This portlet is just a IFrame to iNotes. It's very close in functionality to the Lotus Notes mail client and even supports encrypted mail. Since its a IFrame, the themes and skins of the portal do not apply to this portlet.It will display with its coffee brown color no matter what you have for a theme and customizing the look of iNotes it not an easy thing to do.Common Mail Portlet
This is a new portlet that has a common look and feel no matter what email system you use (Exchange , Lotus Notes) and is new with Websphere Portal 5.1. I have not worked with this myself but there is a nice article on the following page with some screen shots:Configuring PIM
. One of the key differences is that this portlet has some of the functionality of iNotes (access to folders etc) and also respects the themes and skins of the portal.
*You can check Single SignOn to your Domino Servers by
a) Login to Portal
b) Replace the URL in your browser with the URL to your Domino mail file
You should be able to view your mail file without having to authenticate with your Domino server.