My tenants have a Google Voice number that goes to my cell phone. 

I then use a skiptrace service to find the cell phone numbers. 

I have called some and sent out about 20 cell phone text messages with a summary of idea to help them. 

I love them all.Linens are expensive, and you need three setsGuests are hard on linens, you'll be replacing them on a regular basisGuests will call the "Emergency Number" a.k.a. my cell phone, for stupid stuff like "how do I use the spa?".

No cell phones, no texts, no online portals and rent payments, no electronic signatures, some email, newspaper ads and a lot of door knocking (I can almost feel some of you more seasoned PM vets nodding out there). 

Box; rent can only be paid by deposit.For your convenience, the nearest location to your home is 123 Main Street, City, or you can execute a bank-to-bank transfer using the routing number provided.If you have any questions, concerns or maintenance issues, you may call or text my cell phone at <Google voicemail>, or you may email me at the address listed at the top of this notice.Please don’t hesitate to contact me with any questions about this transition or any other pertinent issue.Sincerely,<you, the PM>

Off to Oregon I went for 20 days with spotty cell service with much anticipation of closing on the new property when I returned. 

Get a local cell number (you'd be surprised what a big deal this is to some people!).

Here's an article about them in the Wall Street Journal, you might see a familiar name in it.

He gave me advise on preventative maintenance, a couple of tips he had learned along the way, and gave me his cell phone number and said to give him a call if I ever had a question or needed advise on a rental matter.