Should you time your emails to be during business hours?

Do customers care if I reply at three in the morning, or will they think it's unprofessional?

It highly depends on the culture of your customer, and how closely you interact with your customers. In the U.S., speed of communication is what's most valued. If most of your customer correspondence is brief, one-off interactions, then it probably doesn't matter what time you respond to them. But if you have many interactions with the same customer, it may be a better idea to schedule your e-mail messages for delivery a little later (say, sometime between 6 AM and 8 AM, your time). If you know your customer is on a normal working schedule anyway, it won't matter whether you send the e-mail at 3 AM or if you schedule Outlook to hold it until 6:27 AM before sending it.

Why? Because if you're communicating with customers from other cultures (or customers with whom you regularly correspond) at 3 AM your time, it could trigger concerns of instability, especially if they know you're a small business. The reason is that they may assume you're burning yourself out. (And maybe since the question has come up, this is a good opportunity to step back and see if you are, in fact, headed down this path.)

A while back, one of my colleagues was on a very erratic schedule because of a new baby, and he was trying to make up hours late at night. At some point, he received a very concerned e-mail from a Japanese customer who was worried that my colleague (and, in turn, our company) was overextended and headed down a path toward burnout. After my colleague explained the situation, our customer was less concerned, but still offered some helpful suggestions on managing a less erratic work schedule while also allowing for family time. Since then, we've been a little more careful to schedule most customer correspondence within a more reasonable working schedule.

I think customers want prompt responses to their question and that is more important than what time I answer.

Once in awhile a customer will comment that I was working late or up really early. But most times customers don't even see the time I answered. They will just be so happy they had a prompt reply and their solution was solved quickly.

I get the impression you are a small (one-man?) shop - I understand about wanting to create a professional impression. However, trying to make yourself look like a more established 'professional' firm often isn't the best way to go - early in my first business I made the mistake of trying to create a substantial corporate image. Jason Cohen has an excellent post on the subject. If you want a great example of small (one-man) start-ups being up front about the size of their company, my favourite is Balsamiq (they are a few more people now, but still very personal).

In short, as others have said already, looking after your customers well is much more important than what time you email them. However, if you want a life at some point, just be careful not to set the expectation (especially for your overseas customers) that you'll always be answering their questions at 3am!

I've sent many an email at 3:00 a.m. in the morning to customers. In the rare instance that the customer notices (often because they're online themselves), I don't think they've thought less of me as a result. To the contrary, I think it shows a level of passion and hard work.

I agree with the others, but have one extra point that may be of interest.

We use MailChimp and they not only allow you to choose what time you send the e-mails but they allow you to customise this by country - so if you are a global business, you can send one e-mail but people around the world will receive it at different times.

We find this works really well!

With regards to emails, content is whats important. Customers want the right answers to their requests. They may even appreciate that you are working late into the night to take care of their needs. Productivity-wise, some people may be more effective at different times of day. However, some of the best advice I have gotten was from this article from Marc Andreessen on personal productivity. I would recommend reading the whole thing as he has tons of great tips, but here is the gem on email:

Do email exactly twice a day -- say, once first thing in the morning, and once at the end of the workday. Allocated half an hour or whatever it takes, but otherwise, keep your email client shut and your email notifications turned off. Anyone who needs to reach you so urgently that it can't wait until later in the day or tomorrow morning can call you, or send a runner, or send up smoke signals, or something else[...].

If you get customers overseas it will be impossible not to answer some emails at 3am their time. So just focus on prompt, helpful answers.

Answer as fast as you can, they want solution not to learn how cool or professional you are by waiting let's say until Monday business hours.

In our company, our motto is "Keep it Real" ( thanks to Ali-G :) )

I do answer emails about Sunday morning and I feel very good about it. So far I think our support return is about 2 hours even during the out of business hours. In my book this shows that you are always behind your customer no matter what.

Think yourself as a customer who needs a solution on Saturday. Get the answer about 4 hours later. Now would you go on an buy the software or would you think

These guys should be totally
unprofessional to work in this hour, I
better be use their competitors who
don't answer their support emails
until they come to work

I see this question pop up all the time and it makes no sense to me. Are you only doing business locally?

If you are doing business only in the US, how many time zones does that cover? What's the time difference between New York and Hawaii? If you are like most firms, you sell all over the world. Time zones have no meaning, other that annoyance of catching up with people in China or Australia.

Finally, how many people actually see your time stamp in the emails? How many of them know whether it is showing their time zone, your time zone, or their server's time zone?

You do need to be aware of the time zones for various countries you do business in. Just to make it convenient to talk with them. Tend to European messages early in the morning so they have a chance to reply by the end of their day.