Yes you can send them a email and ofter them a gift to try SFI out and there is alot of people in SFI also have another program they used with SFI belive it or not that they say it goes hand to hand in building your business.
But your main key to get there attention will be, what you say to them like why you join SFI for and what your looking to get out of SFI in the long run.
That will be your main key if your get them back into SFI.