I tried to compile a list of common mistakes that students often make while reaching out to their prospective supervisors for graduate admissions in the US or Canada:
Grammatical and Sentence Structure errors:
Make sure your email does not have grammatical errors. Clear and effective writing is essential to your graduate admission as it gives your prospective supervisor an idea of how well you can write in your area of research. Avoid complex sentence structures and convey your message in plain language. Complex language does not always indicate your competence and could be your prospective supervisor’s biggest pet peeve.
Understand North American Culture:
Avoid extreme humility and flowery language. Instead, the email should concisely focus on your research projects and explain how you could advance the professor’s current research. Be mindful of the reader’s time; they may not invest more than 5 to 10 seconds to decide if they should continue reading the rest of your narrative.
Contact one professor at a time:
You may find more than one professor who could fit your area of expertise; however, try avoiding emailing multiple professors from the same department simultaneously. There may be a possibility one professor might be discussing your profile with other professors in their research groups. Mass emailing will indicate a lack of objective on your part and a loss of alignment with any professor.
Avoid Hyperlinks and Attachments:
Avoid putting hyperlinks in your narrative that redirect the reader to the third party’s website. Although this is my opinion that people may disagree with, I would discourage students from sending their research proposals in their introductory emails. Instead, you might want to exchange emails or talk with the professor to understand the research better before sending your proposal.