Work emails

Today I was reviewing last week's emails at work before deleting them
and the people I work with look over my shoulder observing the screen.
OK, is that insecurity or curiosity? My work emails are boring, mostly
about customer problems and interesting questions I get asked. It would be really stupid to complain about a boss on an email address owned by the company. My manager agreed on that. Once a company who reads our company emails complained about chain letters being sent through our work email, it is for office use only the email complaint said. My manager had to send an email to an ex-coworker asking her to stop sending chain letters.
Sometimes I vent frustrations about coworkers, but I never open those
when that coworker is present because people look over my shoulder. Besides that, if I can't complain to their face what they did wrong then I should not be whining in an email about it to my manager. Most people figure out when I'm rolling my eyes or scoffing that they upset me. I read in a catalog that if you can't say anything nice, a blank stare usually gets the point across.

Other times if something funny happened with another coworker I'll ask
them to read it before I sent it to my manager to make sure I recited it
correctly. I'm pretty open what I put in my work emails to the manager.
If someone wanted to know what the email was about, all they have to do
is ask.