IncrediMail

IncrediMail is an e-mail client which produces multimedia e-mail.

Its free ad-supported version is available for download at its website. The paid version, IncrediMail Premium, removes its advertisements.

The product is intended to be user-friendly, and it employs a Graphical User Interface and multiple templates. The program offers both audio and video embedding in e-mail messages.

IncrediMail-authored e-mails do not require the program to exist on recipient machines, but the e-mail servers do need to enable the IncrediMail formats.

Some people think the program would increases message sizes (and consequently download times for recipients) and uses more bandwidth than text-only or HTML mail. But if you are willing to have a look at the preferences you can switch it to sending plain text messages, which are by very nature the same size with every program.

Description courtesy of Wikipedia.