I have been using Mail for quite some time now. There doesn’t seem to be an equivalent replacement for Mail because it’s so easy to use. When I opened Mail for the first time, one thing that puzzled me was the layout. I was so used to Outlook’s layout which has three equal vertical columns. It got extremely annoying to view mail messages with the wide horizontal columns. A very smart developer made Letterbox, a plug-in that “hacks” Mail and gives it a three pane layout with vertical columns instead of horizontal ones. You can adjust the column width to your liking so the columns look even. The advantage of using Letterbox is that it makes reading messages a whole lot easier.