There is a category of English that exists only in work email. Nobody speaks this way. Nobody has ever said "per my last email" out loud to another human being and meant it kindly.
What makes these phrases dangerous is that they sound formal, and formal feels safe when you are annoyed. So the more irritated you are, the more likely you are to reach for them, and the more clearly the irritation comes through. The phrase is a tell.
Six of them, and what the reader hears.
"Per my last email"
Reads as: I already told you this and you did not read it.
That is not an exaggeration of the subtext, it is a fairly literal translation. The phrase exists to establish a record. It says there is prior correspondence in which I was correct, and I would like that noted.
Sometimes you do need to point back at something. The fix is to point without the accusation attached, which usually means quoting the useful part instead of referencing its existence. "Sending the file again in case it got buried, it is attached below" does the same work and costs you nothing.
"As previously discussed"
Same family, slightly more legal. This one shows up in scope disagreements almost exclusively, which is how everyone has learned to read it: as the opening move before someone cites a contract.
If you are actually establishing a boundary, say the boundary. "The current scope covers three revision rounds, so this would be a fourth." Direct, factual, no history lesson.
"Friendly reminder"
The word friendly is doing a job here, and everyone can see it doing the job. Nobody labels a genuinely friendly message as friendly. We only announce warmth when we suspect it is missing.
Delete the label and just send the reminder. It reads warmer without the adjective than with it.
"Noted"
One word, no verb, no warmth, terminal punctuation. In most offices this has become the standard way to end a conversation you did not enjoy.
The tragedy is that plenty of people use it meaning simply "yes, received," particularly in Indian and Southeast Asian offices where it is genuinely neutral and extremely common. If your client is American or British, it will not read that way. It will read as a door closing.
"Got it, thanks" is two words longer and completely safe.
"Thanks in advance"
This one is subtler and I defended it for years before I saw the problem. You are thanking someone for a thing they have not agreed to do. The gratitude is pre-registered, which means declining now requires them to also decline the thanks.
It is a small manipulation. Most readers cannot articulate why it grates, but plenty feel it. Move the thanks to after they help, where it means something.
"Just circling back"
Circling is what a vulture does. I am being flippant, but the metaphor is genuinely one of hovering, and the phrase has been used so many times to mean "you have ignored me twice" that the original meaning is gone.
Say what you are actually doing. "Following up on the contract" is fine. Or better, give the reason it matters now: "Checking on the contract since we are aiming to start Monday."
The pattern underneath all six
Look at what they have in common. Every one of them is a formal wrapper around an emotion the writer did not want to state.
That is the whole mechanism. When you are annoyed and cannot say so, you reach for the most institutional phrasing available, because institutional feels neutral. But neutrality is not achieved by formality. Formality in a short message reads as distance, and distance from someone you normally speak warmly to reads as displeasure.
The reader does not consciously decode any of this. They just finish the email feeling slightly worse and cannot say why.
What I do instead
When I catch myself reaching for one of these, I take it as a signal rather than a writing problem. The phrase showed up because I am irritated. So the question is not which words to swap in, it is whether the irritation is legitimate and whether I intend to raise it.
If it is legitimate and I want to raise it, I raise it plainly, which almost always goes better than I expect. "This is the third time the feedback has come after the deadline and it is pushing the timeline out. Can we agree on a fixed review day?" Nobody is offended by that. People are offended by "per my last email," which says the same thing while pretending not to.
If it is not worth raising, I write the message without the phrase and let it go properly.
The one thing that does not work is the middle option, where you keep the irritation and hide it inside formal English. The client gets the irritation anyway. They just do not get to respond to it, which is worse for both of you.