Price for upgrading from Rebex Mail to Rebex Secure Mail depends on number of days after initial purchase or support contract renewal:

• Within 90 days after the initial purchase: pay price difference only ($100 for 1-developer license)
• Support contract is active or support contract expired less than 30 days ago: purchase with 40% discount ($209 for 1-developer license)
• All other situations: purchase with 15% discount ($297 for 1-dveloper license)

For more details see "Upgrades to higher edition" on the following page http://www.rebex.net/shop/upgrade.aspx

To purchase the upgrade please write us an e-mail to support@rebex.net with information identifying your initial purchase (order number or an e-mail address you've purchased from)

UPDATE

Since March 2012 there are no longer two separate versions of Rebex mail component. There is only Rebex Secure Mail. Every user who purchased the Rebex Mail less than year ago was upgraded to Rebex Secure Mail for free.

For details see following blogpost: TLS/SSL support included in all Rebex FTP and Mail component variants