Cost me 11k to have house remediated.

With two kittens when they move out you will need very likely need to do remediation as the home will smell like a litter box.

Talk to your tenant and let them know you are recieving complaints from a neighbor/s and maybe they can remedy the situation.

. =)I do know my normal remedies, both legal and via the code office etc, but I'm trying to avoid both.

The seller has multiple remedies to get the property back in case of default.  

Do you about what to look for to avoid or remedy these?

My advise is to immediately start getting the place ready to re-rent and advertise, and simultaneously get a lawyer (or yourself) to send an official letter outlining everyone's responsibilities and remedies.

Additionally, the seller must provide a written notice of default that advises the purchaser of:a) the nature of the default, including the amount if the default is a failure to pay;b) the date by which the purchaser must cure the default or the option will be forfeit; and c) the name and address of the seller or the attorney for the seller.The notice of default must be served by hand, sheriff, or certified mail or equivalent.What if the purchaser does not remedy the default?

As far as your tenants, regardless of you or the PO remediation of the mailboxes, they should not be drawn into what is between you as the landlord and the PO.A side note, when I purchased my SFR primary home, the mail was delivered to a cluster box and still is.

Thomas S.I agree with Greg,I would send him notice of balance due on his rent,  for rent owed, you don't carry forward back rent because someone(TRA) paid current rent on his behalf, he's still responsible to make sure his rent is current and no balance is due.If he doesn't remedy the situation or ask his TRA to come up with the funds he needs to stay in the unit, then I would proceed to file for eviction.Don't confront him by yourself, take someone with you if you have to deliver notices, And at the least I'd give him proper notice of non renewal when that comes up, even if he pays what is owed, at least then you'll have a head start in ending his tenancy.Check your local state laws for eviction proceedings, and non renewal notices.