Outlook integration without using Exchange Server

Hello Friends,

Could you please give me a solution to implement integration of Outlook mails with Navision 4.0 SP1 or higher, without using Exchange server, Can we use SMTP or JMAIL or Other applications to send or receive message from/to Navision and can be recorded for sales person as is being done using the Exchange server.

Also, Please specify, Is Navision 4.0 compatible with exchanger server 7 or It can only work with Exch. Server 5.5/2000.