How do you prove you sent a "Notice to Vacate?"

[Vincent Plant]

So my rental property's lease is coming to an end on 7/31 of this year. I want them out and do not wish to renew. The lease states that I must give 60 days notice to the tenant if I do not wish to auto renew. 

My tenant is very open that they do not wish to leave. 

So, I sent a certified letter containing a notice to vacate. This was unsuccessful, she never signed off on the letter. 

Sure, I'll email it, hand deliver it, whatever but do I need to do anything further to PROVE that I sent this notice? Obviously she won't sign it. Even if I place it in her hand how do I actually prove that I gave it to her. Or do I even need to take it that far? 

[Tchaka Owen]

@Vincent Plant - several suggestions:

1. send it again with receipt (ie, USPS delivered it without tenant signature)

2. email a copy 

3. post on door and take several pictures: 1 up close to show it's the letter, 1 back a bit to show the door (and hopefully house number).   

If you're local, do all 3 and it will hold up in court. Good luck!