To really dislike colleagues like this?!

[sleepyyetawake]

We had someone join our team and they’ve probably been there 5 months now.

He continually sends out emails to the team that only a manager would send. Such as reminding everyone to turn off their computers, to not do work a certain way, lecturing us etc

It’s s team of 20 with two managers and he is no higher than any other team member,

That would irritate me.

That must be irritating. I would have a word with one of the actual managers

Does he have ambitions to be a manager, or is he just a pedant?

Is he ambitious? Was he higher in his previous role?

One of your actual managers should be having a quiet word with this one, I think (unless they're glad he's taking the flack for things they could or should be telling people?)

YANBU

This would irritate me a lot. I would be sending these emails to my junk folder

Does he also do it verbally?

Depends what other stuff is? The turning off PCs thing may just be because he is being green. Annoying but ignorable

Does he also send the emails to the managers or is it just his peers who get them?

A manager needs to address this. Drop a few subtle hints m..

Doesn't he annoy the managers?

God that would really annoy me. We have a manager who doesn't do her actual job sends out shite like this. We got one reminding us to change a passcode and then another one saying we all had to email her to confirm we had changed for passcode. I said I'd done it but hadn't actually bothered. Take that!!

YANBU .....next time reply to his/her email saying ....

Dear ... thank you for your timely reminder to turn off my computer at the end of my working day. I do so appreciate it when colleagues send out such helpful emails (not!!!) .... Best Regards .... Sleepy

.....or, alternatively ..... Dear .... Ref your email about turning off computers .... kindly desist from being such a knob. Regards - Sleepy