Let this be a lesson to all of us that if we pay a fine via mail, send it certified or something that states it has to be signed for! My accountant always tells me to do this when I owe money to the IRS. Never thought about it before, but yes....how would you know whether it got there or not? Are we paying that much attention to balancing our checkbook? I would probably think that a long lapse in depositing the check was just government slow pace!Apparently the bank shows your check as not cashed....otherwise they can give you a copy of the back side of the check for proof. Unfortunately I feel your check is sitting in someones "in box". When they find it and see how late it took them to process it....they will just shred it rather than try to recoup your loses.
I used to work for an insurance company and people would come in with copies of their cancelled checks proving they had paid their premiums....yep, our mistake! We would cancel their late fees and reimburse them for bank fees.
But in your case.....send the check certified mail next time and keep your post office receipt for record. The couple extra dollars to mail it that way is a lot cheaper than the alternative fees for "not getting there".
So sorry this happens to anyone. Good people who really did have "the check in the mail".