My list of gripes solely related to email;
1. People who communicate solely through emails so they have a track record of every conversation. That little black curved thing next to you is called a phone; use it.
2. People who try to be slick by bcc'ing people on emails. Usually this happens when they miss or are going to miss their deadlines and are looking for a scapegoat
3. Getting responses like "huh?" or "come and talk to me instead of emailing" after I dumb down a response to their retarded question as much as humanly possible in vain hopes of thinking they'll actually understand this thing called "how to do your own work".
4. People sending me invites/meeting/appointments without asking me first. Then getting pissy when I say I can't make the meeting as I already have another one planned for that time. There's this thing called a company schedule, look at it next time you try to set an appointment.
5. People who send emails as if they're posting a tweet. Looks real professional when people at your company send emails containing things like "K Thx" or use "ur" instead of your. Idiots.
6. People who send an email to the entire company, wait for a response, don't get one, then complain to the CEO that "no one is doing their job".
7. And lastly, people who miss their deadline due to excessive Facebook/Twitter binges and need to get the job done, send out a mass email to all departments trying to pawn their work onto other people. When the sh#t hits the fan, their response? "Well, I sent out an email but no one bothered to respond....that's why the task isn't completed yet.
Old creaking PCs that take 15 minutes to boot up and come with a mouse which uses a wheel!
We actually still use the mice with the little trackball inside

You know, the ones where you got to clean out the lint every so often. We got like twenty of them still brand new in the box.
Which reminds me of another thing. Having to buy your own crap since the office is too cheap to buy anything that's even remotely "new" in terms of technology. WE STILL HAVE/USE PENTIUM II DESKTOPS FOR CHRIST SAKE!