If you were able to find four properties at $200,000 each, putting 25% down, you would be earning roughly $1,500 a month on principal on a 20 year note on mortgage payments in total.
If you were able to get rent $500/mo over the mortgage of roughly 1,300/mo, then you would have an additional $2000 a month, meeting your goal of making $3,500 a month. Factor in some depreciation and you're making some tax benefits on top of that.
Ignore that the property will have repairs, vacancies, HOA, and potentially management fees, and you're set?
Finding a 200,000 rental going at 1,800 a month isn't easy, though, and rentals are far from invest and forget.
The other option is to invest it in a 7% return, wait 23 years, and voila, you've got a 4% SWR for eternity.
(Just ignore inflation on that)
What about some realistic options-Rephrase the question to take out the "starting today."
If $3,500/mo is what you needed, and you had $200,000 drop in your lap, what would you do to achieve that number as expeditiously as possible?
I'd like to think I'd do the same as above, putting any overage towards a 6 month safety net on the properties, then put anything (including my savings) towards one house, then snowball those savings to the next one. Once they're paid off, work one more year to save up some funds, do every long term repair imaginable with the savings(roof, a/c, etc.) and then I'd feel comfortable resting on those laurels. I might even hire a property manager with all the extra cash from having paid off the mortgages and rent appreciation!