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Building Email Lists for Startups: Best Practices

By August 23, 2016Strategy

If you’re starting a new company, you’ll most likely want to build an email list of contacts so that you can communicate with customers and potential customers. Email marketing remains one of the most effective tools for online marketing. With tightening spam laws and restrictions, it is important to know best practices for list building and bulk emailing to contacts.


Most email platforms (Constant Contact, MailChimp, iContact) and marketing automation platforms (HubSpot, InfusionSoft, SharpSpring) have strict requirements regarding using their system to email contacts. They require that any contact you email has explicitly asked to receive emails from you with either a single or double opt-in. A single opt-in means that someone has subscribed to your email list in some fashion; a double opt-in means they have subscribed and you have sent them a confirmation email with a link that they click on to confirm that they want to receive information from you. Double opt-ins are a valuable way to help score your contacts for their level of interest.

List Sources

It’s important to know what sources of new contacts are acceptable for direct email. When importing contacts, most email and marketing automation platforms require users to state where a list originated. You might be surprised by what sources are not considered to have opted-in to receive emails. This includes:

  • Customers
  • Trade show leads
  • Business cards
  • Attended an event
  • Followed you on social media

Infusionsoft, for example, requires you to submit the URL of the page with the form someone submitted granting permission to receive emails.


HubSpot requires you to confirm that your contacts expect to receive emails from you and to initial the page where you confirm this. MailChimp does not allow purchased lists of any kind to be used.



Email platforms will suspend you from sending lists if an email you sent receives a high percentage of  hard bounces (invalid addresses), soft bounces (email is delivered to the recipient’s server but doesn’t make it to the recipient’s inbox, often a sign of a full inbox and an unused account), spam complaints, or unsubscribes. The acceptable percentages vary from platform to platform.

Spam Keywords

One way to keep your list healthy and to avoid a high percentage of spam complaints is to avoid using spam keywords. Spam filters look for certain terms that indicate spam. Some keywords like “free” in the subject line are frequently used by spammers and may send your email to the spam folder. Other phrases to avoid have to do with exaggerated claims common in spam like “stop snoring” or “earn millions.” Even if you aren’t promoting something spammy, you might use a spam term in your copy. For example, if you offer a natural sleep aid, you could write, “we may not be able to stop your spouse from snoring, but we are able to help you sleep better, naturally.” Most email and marketing automation platforms supply a list of spam keywords they recommend against.

Email Grammer

USING ALL CAPS WILL GET YOU FLAGGED AS SPAM EVERY TIME. Don’t do it. It’s the email equivalent of yelling at someone. People don’t like to be yelled at. A study by the Radicati Group found that more than 85 percent of email users prefer an all-lowercase subject line to one in all caps. Exclamation points in subject lines are another no-no. They are unprofessional and will be flagged as spam by the recipient or the Internet Service Provider (ISP). Another thing that can make your subject line and/or email look unprofessional and spammy? A HubSpot study found that 69 percent of email recipients report email as spam based solely on the subject line. Instead of these spammy tactics, use personalization and segmentation as much as possible to send relevant messages to the right people.

Make it Mobile

Litmus, the company that measures email opens, finds that more than 50 percent of emails are opened on mobile devices. This means it is important to make your emails mobile friendly or they will be unsubscribed, marked as spam or merely deleted. Apple’s phone and tablet email apps account for 39 percent of mobile email opens. Android and Gmail apps account for 25 percent. Preview emails in a mobile tool and or/test them on each type of email reader.

Stay Engaged

Internet Service Providers prioritize emails based on many factors, including engagement. ISPs favor senders who have engaged recipients, and will give preferential deliverability to them.  This means your emails will get sent faster. Senders with large segments of unengaged recipients should expect to see soft bounces, where emails don’t reach the recipient. If you remove unengaged contacts, you should see your email delivery speed and inbox improve. It’s a good idea to remove contacts that haven’t taken action every few months.

Remember Your Goal

It’s important to remember when building your email list that in the end, you want to find the people that are looking for a solution to the problem your product solves. You are not trying to trick people into buying something that they don’t need. Using only opt-in email addresses may mean you send fewer emails, but you should really be focused on communicating with the people that want to hear from you. Error on the side of transparency and your list will be a source of value for your business, delivering information people want, when they want it.

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