Maybe the face-to-face conversation is the main communication, and the e-mail is just a follow-up confirmation.
BS. I want everything in writing for when I get blamed for the other guys fuck up.
There are times where it makes sense to do this.
* Sender is afraid that some of the e-mail contents may come off as negative
* This e-mail is getting copied to your boss or to a group that includes higher-ups
* Sender wants to make sure what they're saying in the e-mail is correct before they send it (in this case they *could* send you a draft first but that can be challenging)
Sometimes they just want to make sure that the permanent message they're about to send is correct or worded well or captures important context.
Maybe if anyone read my emails I wouldn't have to verbally confirm that they've seen and understood the email
Or send and email and immediately walk over to my desk and say 'Did you see my email? Let's discuss.' Can I just respond to your email?! I'm just going to read it while you creepily look over my shoulder, tell you my response that I will also email to you. We can skip a step hear. Also, I was doing something else, this isn't that important.
"Hey, I just sent you an email, can you...."
You didn't read the email. Lets be honest.