George-
I only have experience with programming with Outlook, and it has been relatively painless.

My best friend here however (MCSE, CNE, CCNA) despises Exchange server from an administration and configuration standpoint. He raves about how Lotus does this and that easier.

I guess from a programmer's standpoint, Outlook might be a better choice, but it is possible that LN is better for many reasons from an integrator's standpoint.

As far as integration with VFP though, oyu could buy a product like idsMail, who advertises complete compatibility with LN, and be done with it.