A few of my favourites:
Help me understand = wtf is wrong with you, how can you be so stupid
Just to be clear = fing listen to me you’ve missed the point so utterly I don’t even know what to do with you
Let’s take that offline = stop wasting everybody’s time with the unrelated BS
Per my last email = I’m done with this conversation and if you keep pushing it I will destroy you.
You clearly didn’t read what I already wrote, so let me restate exactly what I wrote in my last email.
Voluntary contribution to the company fundraiser = if you’re the reason my department doesn’t have a 100% participation rate, you’ll never advance
Let’s take this offline = Quit wasting everyone’s time with dumb questions.
“This is not a trivial change request”
This wasn’t in the requirements, and I’m not doing it unless you pony up the big bucks $$$$$$$
AKA spend more time developing requirements beforehand and/or quit changing your mind halfway through development.
I might not have time to look at that for a bit = I will never do that
Have you checked with x? = why the **** are you bothering me with this before confirming with x
“Those DW Simpson Salary Surveys are overstated” = “We will never pay you market rate.”
The last one is used a lot in meetings here lol
“Culture of discipline” = “Good ol’ boys network”
What’s the background on this = this seems really stupid, but some VP probably thinks it’s important, which one?
What are you actually asking for? = Stop trying to trick me into saying yes to something that I would say no to.
Can you come see for a minute so I can discuss something (in the subject line with empty body) = I done effed up, good thing I wore my brown pants today (as in, I done effed up, not the sender of that message)
on page xx of the manual it says… = read the f’in manual
Thats what teams messages are for?
Help me understand your post.
Well, if you want to speak privately its a bit passive aggressive to do it via e-mail with a header message with no body.
Thats what IMs are for (teams or slack).
I’ll check in my files and get back to you = Go away, you bother me. 
I think the passive-aggressivity mainly came from above the sender.