iMapper for Mac

From Mountain Rose Multi Media:

iMapper is an IMAP notification manager. It can be used to list all e-mails received on your mail server (IMAP server), without having to load these mails completely.

You can use iMapper to check your e-mail accounts in the background. When new e-mails arrive, you will be notified.

To show you whether e-mails contain useful information, or whether they are just spam, iMapper provides a preview functionality.

iMapper offers you the following features:

• List e-mails waiting on your server
• See the e-mails waiting on your incoming mail server.
• Multiple Accounts
Check as many IMAP accounts as you want, each with its own check interval and each with its own notification type.
• E-mail Alerts
You can specify special alerts. When one of your important contacts send you an e-mail, you'll receive an extra notification..
• Sounds
You're not only receive a visual notification, but iMapper also plays a sound for you. You can choose from one of the twelve build-in sound or load your own. Each notification can have its own sound.
• Leave E-mail on server
iMapper wil also work if you have your mail client configured to leave the mail on the server.
• More free memory
You don't have to keep your e-mail client loaded to see if there's new mail on the server.