Axapta and Exchange Server

Hi all, We plan to start using the CRM module from Axapta. I know that you can end a mail through Axapta when you have Outlook installed. Is it necessary to have an Exchange Server, or will it be a requirement for the next version 4.0? of Axapta. At the moment we use Mdeamon as a e-mail server. I would like to know if there are reasons to swith over. Any info on this matter will be welcome. Thanks Anne