There should be a servicing part of the file which contains correspondence, accounting, and interactions.  

I would appreciate any advice and I look forward to corresponding with any of my fellow investors.

Farming operations have scaled correspondingly and what was the family farm of my grandparents is no longer sustainable ... in the areas where my parents grew-up, many "family" farms today are working  6 - 10 sections annually - a task that requires millions of dollars in capital equipment.There are also farmers who are specializing in organic and/or non GMO crops (both of which may require maintaining a wide border strip between their fields and their neighbours crops).There were (and likely still are) two principal ways of renting farm land in that area: a) straight rent per acre/quarter/section or b) a share cropping arrangement with the farmer working the land.  

Make sure that you issue your notice with an expiry date corresponding to their rent due date.

My mother was a correspondent/ wholesale lender during the 90's and 2000's and has worked in the lending industry for over 40 years.

Agreeing to split the profits," which are currently uncertain and variable, is very different than "I'm contracting you, my son, at a fixed contract rate to rehab a house I'm flipping" and the corresponding tax treatment that follows is very different.Agree that the OP should speak with his CPA to clarify the original intent and goals. 

If they don't do that, I don't bother corresponding.

(Home-study/correspondence courses are not accepted.)

For all our suppliers we use purchase order numbers, corresponding to an address.

@Robert Ped You have to have a pre-approval letter if you want to be taken seriously.Find a mortgage banker that does direct loan with Fannie/Freddie/FHA/VA and also has correspondence agreements with other investors.