Zimbra server and windows

[Andy Latham]

I am a newbie so apologies if this is in the wrong forum.
I have a customer that would like to replace Exchange with Zimbra. We have done testing and everything looks fine.
Can anyone tell me if it is possible to programtically send an email from a windows client (via VBScript) to the Zimbra server?
Is there a way of calling the Zimbra desktop API in the same way I could invoke a MAPI client.
Thanks for your help

Andy