A double email opt-in sign-up requires that a user confirm that he or she has actively joined your email list. This is typically done by generating an email to the user after he or she signs up. That email then requires the user to click a link in the email in order to confirm that he or she is the owner of the email address and does want to receive emails from you.

A double opt-in solution also comes with a number of advantages and disadvantages. The advantages of a double opt-in sign-up process include:

Better Quality List Protection: As we previously discussed, at the end of the day it doesn’t matter how large your email marketing list is if the list is not predominantly high-quality addresses. Without a double email opt-in, you risk keeping bad email addresses on your list. In addition to the examples noted above, malicious competitors may flood your single email opt-in form with bad addresses simply to degrade your sender reputation. A double opt-in email sign-up protects your list, your company, and your subscribers.

Opportunity to Communicate with Subscribers Immediately: A double opt-in email sign-up process also gives you the ability to communicate with your subscribers immediately in the confirmation email. You can tell them more about your brand, ask them to add your email to their personal white list, or even provide a special email offer. This allows you to put a communication in front of them while they are still thinking about you after having signed up.

The disadvantages include:

Slower List Growth: A double opt-in process will mean that your list grows more slowly. It requires more work of the user and often results in “lost addresses” as described below.

Lost Addresses: Whether it’s because they simply lose interest or because your confirmation email goes to the spam or junk folder, many email subscribers will simply not follow through with confirming their subscription, and you will have lost a potential marketing lead.

More Tech Resources Required: If you are building your own proprietary email marketing solution, a double opt-in system will require more tech resources. If you are using a third party email provider such as Comm100, you won’t need to worry about these additional tech resources!

All good marketing involves testing! If you’re unsure which sign-up solution is best for your business goals, try using a single email opt-in for a month and then a double opt-in for a month. Track sign-up volume, spam complaints, bad email addresses, and overall email list activity. Then compare each against your goals and determine which the best solution is for your company.