Certified letter mailed to tenant for rent increase...

[Vanessa S.]

My property is in CA and per CA law, 60 days + 5 days is required if notifying them via mail of a rent increase. Per the USPS today (tracking system online), there was an attempt to deliver the certified letter but no one was there to receive it or sign for it. The letter carrier left a notice for them that an attempt was made. Here is my hypothetical- what if my tenants aren't home again to sign for this letter and they do not pick up the letter after receiving the notice to retrieve the letter at the local post office? Should I notify them electronically as well? TIA for your input!