<human>: Hi guys, 

So I'm in Chicago and I am having a problem with a Landlord. Basically I moved out of an apartment about a month ago and am out of state working. My landlord wanted me to either try and bring my apartment keys to her or get them to her somehow. We agreed to send them through the mail(I have a text from her that say this is ok) and so I sent them, but when the envelope got there the envelope was slit open on both sides and there were no keys in it. Now she wants me to pay for the change of locks on her doors for safety reason. Paying for this kind of thing is part of my lease if I loose the keys but I'm not sure that them getting stolen/lost in the mail is on me? Am I correct in this thought or am I required to pay for the lock and key change?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: Sent apt. keys to landlord, they were stolen/lost in mail and I'm not sure I am responsible to cover charges on new locks. Help me /r/legaladvice you're my only hope.