Was developed as perspective project, but it hasn't been continued because of mistaken technology of program developing. But idea is good and I think it's not too bad to fully rewrite it. And this project is nice demo of using Indy 9 library for applied software.
With Avanti! you can check and send your e-mail, you can view only headers of new messages and choose letters to download/delete/storage on server. Avanti! supports HTML and plain text messages, views Message Server Information, has templates with auto-replace variables. Furthermore, this software will support multiple accounts and has simple mailchecker.

Avanti! Features:
1. POP3/SMTP support
2. OpenSSL connection type support
3. Adapted for use on rewritable devices (USB flash drive, in sample)
4. View and edit HTML-messages (strong visual HTML editor)
5. Templates for New/Reply messages with dinamic variables
6. Mail-Manager (view headers of new messages and choose some of them to download)
7. QuickMail - tool, which checks your accounts for new messages automatically
8. Correct work with attach
9. Multilingual interface
10. View full e-message headers

The license of this software is Freeware, you can free download and free use this email client software.