I would like to know the websites which offer customized mail marketing at feasible prices or is there any software which helps us to design the mails as per our preferences.Thank you !

@Ryan Cleary talk to some custom home builders and general contractors. 

Either mid century, rustic farm, or boho decors, they played important role in bringing customers.

This might be more exceptional, but I believe being responsive as I describe helps us build rapport with our tenants (customers) and I think it's a big reason why we experience very low tenant turnover. 

Airbnb works, because its one of the goto. kind of like Kleenex is a face tissue, same with airbnb is the tag line for STRs. although lately airbnb customer service has a lot to be desired.

If you are creating a customized partnership, you might be headed in the right direction to make sure everyone knows their split and role.

I do a little of everything, including: spec building, custom builds, multi family, and student rentals. 

@Stuart Grazier and his partner at Storehouse 3:10 Ventures are both active duty military and a significant number of their customers are military as well.

Leave a stack at local business for them to hand out to their customers.

However, keep in mind that, unless it has street frontage, the only customers you have will be your residents.