From the makers of the SoftMaker office suite, this surprisingly comprehensive mail client is especially good at synchronizing with Gmail, including Google Calendar and Contacts.

It can also import from Microsoft Outlook, a big plus for anyone looking to migrate from that program. The free version limits you to two accounts; if you need more, the unlimited Pro version costs $49.95.

My one complaint with emClient: as with Thunderbird, any message you reply to or forward isn't automatically marked as read -- a rather ridiculous oversight, in my humble opinion.