Mail.app vs eM Client

One thing Apple does well is to integrate its apps and hardware. The mail app is no exception. If you must be in the hermit kingdom, at least take advantage of the (often excellent) features provided.

Since it's the built-in Mac email client and is quite complete feature-wise, most users will not really need any other third-party applications out there. Mail.app should be enough for their needs.

Mail.app has powerful markup tools which let users add annotations to images or even sign documents they got through email without ever leaving the client.

• You can choose out of tenths of mailheaders (several hundreds including virtual headers)
• "<header> is (not) in <folder> <header>" operator which enables you to do cool filters
• Each smart folder can have smart subfolders by an user definable key

If the basic features inside Mail.app are not enough, it can easily be extended through plugins to add new features.

Such as sorting through categories, etc.

It is free for 2 accounts and as long as you don't use it commercially. Paid version comes with support and can handle more than 2 accounts.

They've been developing and improving it consistently for years.

eM Client seamlessly integrated the Quick Text extension that was available on Thunderbird. This makes it easy to quickly auto-insert dynamic text, based on many variables, saving time and the need to tediously repeat manual text replies.

eM Client includes integrated chat, so you don't need another application for chatting with your friends. All common chat services supported (Google chat, Jabber and others).

eM Client sends straight .pdf files for fax messages flawlessly.

It saves space, unlike Thunderbird.

But only because it has no alternative.

It provides (almost) complete Gmail functionality (calendar, tasks, chat, contacts), while offering advantages of an application: offline use, more e-mail providers in one place, very good design, support, etc.