I got an email from professor M asking me if I will have time for a tea with her on Friday, and then I came up with this question:

Even if it is an important email from your professor (e.g. select your thesis or advisor), when you need some time to think before you make the final decision, how fast should a student reply to the a professor's email before the student is considered a lazy student, or a student who tries to slack off in studies?

If I write the reply to my professor's email after 3 days, will she get angry or even unfriend me?


5 Answers 5


There isn't really anything special about academia in this regard. If someone sends you an email that needs a response, it is always courteous to respond as quickly as you are able. It doesn't matter if it's to a professor or a student or a friend.

Anyone might get annoyed with you if you take a long time to respond to an email to which they need a quick response - not just professors! But there's no magic number - you can't say that 71 hours is fine but 73 hours is excessive. Some messages are urgent and need a quick response, others are not. If someone is expecting a quick response but you need more time to make a decision, you can certainly contact them to let them know you are considering it, and ask when they need your answer.

As a general note: several of your recent questions seem to be written from the assumption that academia has its own special unwritten laws for everything, and if you can only find out what they are and obey them, everything will be fine. For better or for worse, that's not generally the case - there are no such objective standards. The key to successful interactions, in academia or any other job, is "act like a decent and professional human being".

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    +1 for "act like a decent and professional human being".
    – RoboKaren
    Jan 27, 2015 at 17:44
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    While I agree with you about there being no special rules for academia, it does have a bit of a reputation for having some irrational professors. Professors have a lot of power over the lives of their students, and some of them aren't afraid of being dictatorial after a certain point (often the granting of tenure). I think these kinds of questions are in response to this reputation. Everyone wants to stay on the good side of tenured profs. Fortunately your advice is a good way to do that.
    – Bill Barth
    Jan 27, 2015 at 17:48
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    @BillBarth - Would recommend you watch Bad Bosses, Office Space, or some episodes of The Office. Faculty don't have nearly the power of office supervisors.
    – RoboKaren
    Jan 27, 2015 at 18:29
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    @RoboKaren, agreed, but I think students fear they have this kind of power.
    – Bill Barth
    Jan 27, 2015 at 19:20
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    But those kind of professors seem to be unlikely to invite you to tea on Friday. If I got that invite the right thing to do is say yes and go and have a good time - an opportunity to get to know a professor better seems hard to pass up.
    – Jon Custer
    Jan 27, 2015 at 21:49

This is more business etiquette than anything else, but you should try to respond to your superiors within 1 business day -- even if it is something such as "Thank you for the invitation, I need to check with my schedule/partner to see if this is a possibility. I'll write back later in the week to let you know."

Responding quickly is clearly best practice, but there's a great deal of latitude depending on your relationships with your advisor (casual vs. formal); your advisor's own expectations of you (lateral vs. hierarchical); the criticality of the request; department culture; and so forth.

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    In fact, when I teach a course, I make clear (in the syllabus or the first meeting) that it is the students' duty to check their mail (or any other communication channel used) at least daily. While I do not expect them to react immediatly on non-urgent matters, I think that it is reasonable to expect that if you, for instance, send a mail on monday morning wether one should meet at tuesday afternoon, the student will respond before tuesday afternoon. (And be it only a short note saying, no, I have no time).
    – damian
    Jan 27, 2015 at 23:11
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    @damian What if the Student checked their e-mail monday morning before you wrote and tuesday evening after the suggested meeting time? That'd still satisfy some definition of daily. In this case I'd recommend that the inviter call the invitee on tuesday late morning if they haven't had a response by then. Jan 28, 2015 at 5:41
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    In computer science as in life there is a principle known as "best effort." Just try to satisfy that requirement rather than worrying about hypotheticals about getting hit by a bus or having your fiber optic cable cut before you respond.
    – RoboKaren
    Jan 28, 2015 at 11:26

An addendum to other answers: prompt response is always good... even if you don't immediately know the answer to a question, it is helpful to all parties to send a quick email saying exactly that. In the case at hand, perhaps "Thanks for the invitation, I'll check the details of my schedule and get back to you as soon as I can. Sincerely, ..."

I would think that the same could apply for research or educational issues: in effect acknowledge the communique, and indicate as best you can how soon the other party could expect a definitive response.

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    I beg to disagree. This approach has two drawbacks. It needlessly wastes the attention of the addressee with two emails where one would be sufficient (aka mail a final answer as it becomes available*). Secondly, a prompt** response sends the subtle signal that addresser has got nothing better to do but check emails when he actually "should" be in the lab, "do science" and whatnot ;) (* if that is to be expected within a reasonable time frame, ** highly dependent on your interpretation of "prompt")
    – Ghanima
    Jan 27, 2015 at 23:05
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    @Ghanima if someone invites you for a tea, and you can't give them answer the same day, it is polite to acknowledge the invitation and to let them know when you will have an answer.
    – afaust
    Jan 27, 2015 at 23:21
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    @afaust, that's what I call interpretation of "prompt". To me prompt always sounds like "nowish" that is within minutes or so. The same day is something that I'd call quite reasonable.
    – Ghanima
    Jan 27, 2015 at 23:22
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    @paulgarrett, not everybody sees permanent access to fast messaging services as a blessing ;) that might include faculty members as well. After all the answers to the question are highly subjective and depending on the character of Professor M (which the OP knows but we do not). And again, in my opinion there's a big difference between "prompt" and "within 3 days".
    – Ghanima
    Jan 27, 2015 at 23:29
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    @O.R.Mapper, I'm a little confused: what point does it make if one pointedly ignores email sent from one's supervisor, while being aware of its arrival, for example? Might have bearing on the work one is doing? All I can infer is that there's a tacit "pointlessness" of messages assumed in other peoples' discussion of this question, and this is mysterious to me. I try to avoid sending pointless emails to my students... Jan 28, 2015 at 13:32

I can only use my personal experience as a guide.

I check my own email at least twice per day. I'm married, so any social engagements or other appointments have to be run by my wife. Getting that settled with my wife will take at most several hours. Most of the time it only takes minutes.

Getting back in touch with someone, in most cases, should take less than 24 hours. There are rare instances when it could take more than 24 hours and then an explanation for the delay would be polite regardless of whom is making the invite.

  • I appreciate your answer but are you sure that people will never regard a short prompt response that explaining the delay is not a sign of sloppiness? Would two emails needlessly waste the attention of the addressee with two emails where one would be sufficient
    – High GPA
    Dec 4, 2020 at 9:28

At the time of letters a reply took time and was generally granted.

At the time of emails and smartphones with 24h-internet-access one can assume that the email, if not instantly, is read at least the next morning. So a reply, if no further work on the answer is required, is awaited on the spot - 24 h seems a good time-frame. Not only in academic field but in everyday life, also.

Unless You are on holiday abroad, where internet-access is expensive.

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