options for payment with new tenants

[Tami R.]

I have around 85 units and by next month I will be doubling my units and will have 175.
I do not have a dedicated office for our real estate, I office out of my husbands and my construction offices/showroom.  Which in the beginning when we had just a couple rentals was fine when a tenant would come in and pay rent but now it's too much and our employees don't like dealing with it and my husband doesn't like some of the people coming in.  

For some reason no one ever likes to mail anything they want to drop it off so we have a mail box that goes into a secured box to our building so we are fine with that.  So i am trying to figure out options for our new 90 tenants....

1.  Mail the dang check - no more cash!

2.  Drop off the check in the secured box but don't even give them the option of going inside?

3.  Because some of these buildings are 11 - 15 units I thought about having a secured box on location but I worry about theft???

4.  Online option?  I use quickbooks and do not want to change my accounting but thoughts on payments online?  i don't wan to make it complicated for the tenant or me.  and again i don't want to change my accounting.. plus we have 3 companies and 3 different checking accounts?  Ideas / thoughts

Any help would be great.  thanks