What is the Best Time to Send an Email Promotion or Newsletter?

Perhaps the most frequently asked question in email marketing is: When should we send our email promotion or newsletter? The short answer - Tuesday through Thursday mornings are generally good times. The long answer is much more complicated, and like most all email marketing questions, depends on numerous variables and your specific situation.

When determining the optimum time to send (I'm defining "send" as when to schedule your email for delivery) emails, you need to break the question down into three parts:

1) When do you want recipients to actually receive your email?
2) What factors drive how long it takes for the emails to actually reach each recipient?
3) Do you have the resources necessary to continuously send emails at a regular predetermined time?

To help answer question #2, I've developed the following "Time to Send Formula" and then discuss in detail the factors that drive all three of these questions.

"Time to Send Formula"

DOT - (IF + SD + QF) = ST

DOT = Desired Open Time - the first hour time period in which you want your readers to receive and open your email
IF = ISP Factor - the duration it takes ISPs to actually deliver emails
SD = Send Duration - the time it takes software/ASP solutions to send a given volume of emails
QF = Queue Factor - the period of time emails may be in the queue behind other email campaigns
ST = Schedule Time - the time emails are scheduled for distribution

Ok, now you are saying to yourself, I didn't realize I needed a calculator to determine the best time to send emails? Well you don't. The point of the above formula is really to get you to understand and think about the many variables in the email delivery process that may be beyond your control. And in particular, that you consider how long it takes for emails to actually reach your recipients in box.

Let's look at each of these five formula factors in detail.

1. Desired Open Time - DOT

Before determining when to send your emails, you need to understand when recipients are most likely to open your emails or when they will take your desired action. Let's look at four key drivers of "Desired Open Time" - Recipients; Open Concentration Period; Environment; and Message.

Recipients - When are your recipients not only most likely to open your email, but take a desired action? Recipient factors to understand include:

• Business or Consumer Relationship: According to recent EmailLabs analysis, the majority of emails are opened throughout the day - about 80 percent between 5 a.m. and 5 p.m. (PST), with roughly 62 percent being opened between Tuesday and Thursday. Clearly most business-oriented customers are more likely to open emails during their workday, while consumer-based subscribers may open emails at any time. Though many people check their personal email accounts during the day, many do not, and so sending in the evening or on the weekends is clearly not out of the question when emailing B2C subscribers.

• Time Zone: Do they live all over the world or mostly on the East Coast of the United States? People in New York, for example, (in my experience) tend to start work later and leave later than people on the West Coast. Janet Roberts, editor of Ezine-Tips, which has subscribers throughout the world, suggests using The World Clock tool from timeanddate.com to help you understand when your emails will reach your recipients. Janet says, "we try to get Ezine-Tips out early enough in the day (U.S. time) so that we catch UK workers while they're still in the office." But beware, with a send time like this most of your subscribers in Australia, for example, are probably asleep. ACTION: If you have a significant number of subscribers all over the world, consider segmenting your subscribers according to major time zone periods - and schedule each segment accordingly.

• Demographics/Psychographics: If you are reaching teens, then late afternoon when they get home from school is a good time, whereas homemakers might be most likely to open emails in the middle of the day. Many people may work in occupations where Internet/email access is either not available (i.e., construction, factory and restaurant workers) or time makes it difficult (doctors, nurses, teachers). Differences in sex could be a factor as well. While the gap is apparently closing, a higher percentage of males versus females are more likely to be online during the prime evening television viewing hours. ACTION: Understand the composition and habits of your subscribers and identify the time period (or periods) that they are most likely to open and act on your emails.

Open Concentration Period - When is the highest concentration of opens?

• This is the period of time - the first few hours after delivery - with the greatest concentration of opens. For example, in two recent issues of The Intevation Report, 37 percent and 38.5 percent of opens occurred within the first three hours of distribution. (I used the Open Histogram feature in our solution for this analysis.) The newsletters were sent at 10 a.m. and 2 p.m. PST, and not surprisingly the email sent at 2 p.m., saw a much larger drop in opens in hour four - which would be 8 p.m. East Coast time. So understanding this open concentration period is key to determining that ideal delivery time - and ensuring you maximize this initial "open burst." ACTION: If your technology solution does not have an open histogram feature, then simply monitor the number of opens every hour for the first 4-6 hours after opening.

Environment - What environmental factors are your emails competing with?

• Competing Time-Sensitive Newsletters: If your content is time sensitive, do you need to get your information in the hands of recipients before competing newsletters? Or does your content provide more analysis such that being first isn't why your readers subscribe to your newsletter?

• Offline Media: Do you publish a magazine, for example? If so, do you want your subscribers to receive your newsletter before, at the same time or after they receive your print publications?

• Peak Spam Waves: While spam arrives at all times, it seems that a lot of spam is sent during the middle of the night and on weekends. If you send late at night or very early in the morning, you risk getting lost among your recipients spam bloated inboxes.

• Message Type: Most recipients of corporate newsletters expect to receive them during the heart of the business day, say 10 a.m. to 4 p.m. News-oriented newsletters are generally expected early in the morning with the previous day's news, or in the afternoon with news from the current day. The key here is timeliness of the information. Promotional and consumer ecommerce emails might be appropriate in the evening, on weekends or during the business day. It really depends on what you are selling and to whom. For example, an EmailLabs client has found that Sunday at 7 a.m. is the optimum "send time" for its mostly adult male motorcycle-riding customer base. ACTION: If you aren't sure what the optimum open time is for your emails, test different days of the week and time periods. Make sure, however, that you test against a control group and that you measure not only open rates, but click-through percentages and Web site actions such as transactions and downloads.

• Frequency: For emails sent frequently (and the frequency is known and expected by recipients), then consistency is really more important than time of day or day of week. If you send a newsletter at least two-times per week, then sending at the same time for every newsletter is recommended. You want recipients to almost be able to set their watches by your emails. For example, two newsletters I've been receiving for a few years arrive at about 3:15 p.m. and 5 p.m respectively - times some would suggest are bad for email. But when my Outlook bell goes "ding" at about these times in the afternoon, I almost always check to see if it is one of these expected newsletters. For monthly newsletters and irregular ecommerce emails, a consistent day or time may be of little importance - but the right time/day could make a huge difference depending on the recipients' demographics and the nature of your content.

2. Send Duration (SD)

Are you sending out 4,000 emails or 4 million? Depending on the technology solution or provider you use and volume being sent, it might take anywhere from a few minutes to many hours for your software or ASP solution provider to actually send the emails out to ISPs for delivery to the end recipient. ACTION: Monitor and understand this duration period and make sure you factor it into your calculations.

3. Queue Factor (QF)

Are you are using an ASP solution or sharing a mail server with others in your company? If so, keep in mind that when you've pressed the send button your emails will go "in the queue" to be sent. If you schedule them on a day and time such as Tuesday morning (when a large percentage of emails are sent), your emails may be in the queue behind many other companies or departments of your company, and may take longer than you anticipated before they are actually sent. ACTION: Understand if the "queue factor" applies to you and add this estimated time into your calculations.

4. ISP Factor (IF)

Not all ISPs are created equal. Some ISPs deliver emails they receive immediately, while others may take an hour or in some cases 12 or more hours to process emails. Secondly, some ISPs utilize volume-based filters, so sending too many emails to a single ISP within a short time frame may cause your emails to be blocked - and sent to the ISP blackhole. ACTION: Consider sending test emails to seed email accounts with ISPs such as AOL, Hotmail, Yahoo and others that comprise 5 percent or more of your list. If one or more consistently shows a significant delay in delivery, consider segmenting those subscribers out and scheduling them for an earlier delivery time.

5. Schedule Time (ST)

If you've followed this far, you now have a good understanding of all the factors that may affect email delivery and open times. So let's put the formula to work with an example:

Formula: DOT - (IF + SD + QF) = ST
Example: 1 p.m. - (1 Hour + 1 Hour + .5 Hour) = 10:30 a.m.

In this example, through exhaustive research and analysis you've determined that the ideal time for your emails to reach all or a sub segment of your list is at 1 p.m. But for this to happen, you'll need to actually schedule your email to go out at 10:30 a.m.

Even if you don't take the time to undertake the analysis outlined above, at minimum you should do the following:

> Put a stake in the ground as the ideal time you want your recipients to open their email
> If you are sending a high volume of emails schedule your emails well in advance of the desired open time. If your volume is fairly low, then perhaps an hour or so in advance might suffice.

Good luck!