Client Communication

Mailings
Limit-point(Trial version)
Download
Excellent bulk mailing application
Revolver Mail
Revolversoft(Free)
Download
Revolver Mail: An Interesting Alternative to Mail and Entourage
Google Notifier for Mac
Google Inc.(Free)
Download
Check your email and events with Google Notifier for Mac
E-Mail Commander
Koingosw(Trial version)
Download
Powerful Batch E-Mailer: E-Mail Commander Review
PowerMail
Ctmdev(Trial version)
Download
PowerMail: A Powerful Email Client with International Support
Kerio MailServer
Kerio(Trial version)
Download
Secure messaging and group collaboration
MiniMail
Olivetoast(Trial version)
Download
Apple Mail messages at your fingertips
RelatedMail
Pertinere(Free)
Download
RelatedMail: Show Related Mails
WideMail
Daneharnett(Free)
Download
WideMail: A Plugin to Enhance Apple Mail's Viewing Experience
GPGMail
GPGMail(Free)
Download
GPGMail: Apple Mail plugin to secure e-mail sending