I own a residential property management company covering Boston and the surrounding areas called Mass Property Management.  

Even the closing papers can be overnighted to you to sign with a notary.I can't speak for the house-hacking route as I've never done it myself (other than I encourage you to be up on running the numbers so you know what you're getting into, as Mass. isn't usually known for high cash flow).

I have read about increasing the rent gradually over time in order to keep the tenants and not have a mass exodus.

I am a franchise owner, and started investing in real estate with my partner two years ego.We mainly did it because at the time, we where paying over a 200k in rents for our stores.We started with one building, that let to two, than 3 etc...today we have two commercial building holding two stores, with another 4000 square feet waiting to be rented in one of the buildingsWe are from Mass, so we started looking into rental units, and today we own 8 rental unitsAll in all we have over 40k in free cashflow that we keep investing, total portfolio is worth about 1.4 million, with equity of about 600k.We want to continue growing, but now we have used all of our capital and trying to work with banks to finance new existing properties.We look at purchasing a 2-3 decker (term in new England for a 2 or 3 family) we try to buy them for 25-35 per door, fix them and be into them for 50-60.

Just bought my first investment single family in Mass.

One of our partners is claiming that this is their way of muscling us into funding some of their remodel; and I tend to agree. 

What software can I use forletter mass distribution formy real estate business ? 

I am in Mass and good deal FC properties are not easy to come by these days...  

Depending on what the money is for, you can take the opposite approach and try to maximize your contribution to a 401K until you have enough money to use the 401k funds to invest in real estate.If you have 401K's you can roll over from previous employers, you can get to critical mass more quickly.If you don't need to live on the money, then you are better off contributing pre-tax to a solo 401K (you get more money to invest) and then delaying paying taxes for a while.

That said, policy and mass speculation does have a very real impact— and while we are in what some might consider an upmarket (considering nationwide real estate market conditions), pay close attention to hyperlocal market conditions (for places where you're considering buying real estate, consider long vs short term strategy).