I'm a 21C teacher who embraces technology and sees value in communicating in ways "digital natives" do.

Case in point:

A student didn't show up for her test. I informed her that she had missed the test using a texting service called "Remind" which allows me to communicate with students and parents through their cell phones.  You can set the service to be "text out only" or allow users to text you back.  I find students and some parents are much more willing to ask for help through texts than in person or by email.  Yes, there are inherent issues with training kids to NOT develop face-to-face social skills but their academic success and self-advocacy skills are heavily developed using digital communication methods.

She promptly texted me back, informing me that she is home sick and cannot write the test and has a doctor's appointment on the alternate test date. I sent her the test, which she can complete at home (it's skill based, not knowledge based) with instructions to her parents that she is to receive no help from anyone.  

A traditional teacher would have either given up more of their own free time and lunch or after school to find a SECOND alternate test date OR given the student a mark of zero.

Is it perfect? No. Does it rely on some trust for the student? Yes. Is it a good workaround? Absolutely.

UPDATE (Nov 3/17): Educators should check their school board's policy. REMIND is banned in some boards.