If nobody uses a cellphone, a computer, or email, you're failing your stories and your readers.
Maybe you'll say such "techy" things aren't romantic enough for your contemporary romance. Cars and landline phones were once new, too, but you don't seem to have a problem with those? And I hate to break it to you, but mobile phones, computers, and email are now decades old. Is every romance/erotica author over 65 years old?
Back in ye olden days, people's lives could be in danger because someone didn't deliver a message. Does technology change that? Nope. Someone's battery could be dead, or service could be out. Otherwise, why do you not have characters texting each other? Why do they not take pictures of each other on their phones? What kind of writer are you if you can't incorporate symbols into your story via digital photos as well as the setting of a scene?
We're long past the point where excluding technology from contemporary stories is acceptable. It's starting to seem weird.
If you write erotica, tech opens up some fun possibilities, such as a Dom(me)s texting commands to their subs, or making their own amateur porn with their phones' cameras. And let's not forget remote-controlled sex toys!
Unless you're specifically writing a story that takes place in the early 80s, "contemporary" means NOW, and now means the ubiquitous presence of high-powered personal tech.
Let's get with it, people.