A client in Austin once replied to an email of mine with a single line: "Revert to what?"
I had written "kindly revert with your feedback," which is unremarkable in an Indian office and which I had typed several thousand times without incident. He was not being difficult. He genuinely did not know what I was asking, because in American English revert means to go back to a previous state. I had asked him to undo something.
None of what follows is about correctness. Indian English is a legitimate variety with more speakers than British English has. This is about what happens when your reader has a different variety, and about a handful of small edits worth making when the money is coming from Boston.
Kindly revert
Means: please reply.
Heard as: please return to a previous version, or nothing at all.
This is the one with the highest cost, because it appears in the sentence where you are asking for the thing you need. Write "please reply" or "let me know."
Do the needful
Means: please handle it appropriately.
Heard as: unclear, slightly archaic, and to some ears faintly imperious, because it instructs without specifying. British readers occasionally recognise it as colonial-era administrative English, which is exactly where it came from.
The real problem is vagueness. It tells the client to act without telling them what the action is. "Could you approve the invoice and forward it to accounts" is longer and does the actual job.
Prepone
Means: move earlier. It is a genuinely useful word and English is worse for not having it.
Heard as: nothing. It does not exist in American or British English and readers will pause on it.
Say "move it earlier" or "bring it forward." I resent this one, for the record. Prepone is the better word.
Please intimate
Means: please inform.
Heard as: awkward at best. Intimate is far more common as an adjective in American English, meaning close or private, and the verb form is rare and formal enough to feel wrong.
"Please let me know."
Out of station
Means: out of town, travelling.
Heard as: military or railway phrasing. Not incomprehensible, just noticeably dated.
"I am travelling" is what your client will say themselves.
Your good name
Means: what is your name, phrased courteously. It is a direct translation of aapka shubh naam and the courtesy is real.
Heard as: confusing. Some readers hear an implication that they might have a bad name too.
Same to you
Means: the same wishes back to you.
Heard as: slightly abrupt, occasionally sarcastic depending on context, because Americans use it most often to return an insult. "You too" is the neutral version and it is what everyone actually says.
Myself Rahul
Means: I am Rahul.
Heard as: ungrammatical, which will affect how the rest of your message is read whether or not that is fair.
This is the one I would change first, because it usually appears in an introduction, and introductions set the frame for everything after them.
The pattern behind most of them
Look at what these have in common. Almost all of them are the formal register of Indian English, and formality in Indian English is built on politeness markers that do not exist in American business writing.
Kindly. Please intimate. Do the needful. Revert. Each one is a courtesy signal in one variety and a friction point in another.
Meanwhile American business English signals respect in a completely different way: through directness and brevity. Short sentences, the ask up front, no elaborate softening. To an Indian reader that can look brusque. To an American reader, our version can look either excessively deferential or oddly stiff, and both readings hurt you in a negotiation about rates.
Neither is more polite. They are different systems for showing the same thing.
What I would actually change
Not everything. Your voice is your voice and clients hire people, not neutral English.
But the phrases that cost you comprehension are worth losing, because a client who has to reread your sentence is a client with slightly less confidence in you, every time, for years. Revert, do the needful, please intimate, myself. Those four.
The rest is optional. Prepone you can keep, and explain once, and half the time your client will start using it.
The wider point is one I keep coming back to. There is no universally correct register. There is only the register that works for the person reading, and if you write to clients in three countries you are effectively writing in three dialects. I got tired enough of holding that in my head for every client that I built a tool to remember it for me. But even without one, knowing that these eight phrases land differently is most of the benefit.