Rent due today. No check.

[Richard Sanchez]

Hello BP, Today is the first month of the lease where tenant was to pay by either mail, person, online. I was at the property doing a quick fix a few days before rent was due and tenet said they mailed the check. It is due today and no payment. According to the lease they have two days before any late payment fee is added (probably should have done same day in retrospect). My question is should I issue a "pay or quit" notice end of day or should I wait another day since snail mail take 3-5 days? Any advice or recommendations would be appreciated. This is my first rental. Thank you.