Try the internet standard protocols, i.e. SMTP to send (TCP port 25 or 587), POP3 (TCP port 110) or IMAP4 (TCP port 143) to receive. Those protocols are often enabled on Exchange servers, if not, talk to the server's administrator. As soon as you know that those protocols work, forget that you are "talking" with an Exchange server and work like you would do with any other internet mail server.
Alexander
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Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)