Double opt-in – 12 setup-tips to get a maximum outcome [2/2]

In one of the last postings we looked at why and when email marketers should consider using double opt (DOI) to grow their lists. But as a matter of fact, DOI adds a new layer of complexity to the email signup. It naturally costs a certain percentage of subscribers (partly 40% and more) because not all complete the process by clicking the confirmation link in their checkmail. There are many possible reasons that, ranging from ‘users not understanding the need of the second step’ to ‘junk-filtered checkmails en masse’. Anyway, this makes it necessary to implement double opt-in very carefully. By using the following 12 tips, you should be able to maximize your conversion rates from signing in to confirming the subscription:

  1. Double opt-in rate: First of all, you should include the double opt-in rate, calculated as new subscribers who clicked the checkmail divided by all email address submissions, into your email marketing cockpit. By monitoring this metric, you can evaluate how changes affect the outcome and what your current status quo is.
  2. “A further step“: After entering the email address you should point out very clearly to the user that a further step is necessary in order to complete the signup process. Stating the reason for the second step helps creating an understanding (e.g. “to avoid registrations by unauthorized third parties” or “to verify the validity of the email address.”). Announcing the sender name and subject line already on the website helps the user to spot the checkmail later on.
  3. “Visit inbox, now”: Directly instruct the user to visit his email inbox and click the confirmation link after submitting the email address. Filtering the email’s domain part to offer a dynamically inserted link to the appropriate webmailer (,, et cetera) makes for a particular elegant solution in this context.
  4. “Add to address book”: Also, ask the prospective to add your sender address to his address book or safe sender list. Communicating the benefits for doing so, such as “to make sure that you will receive your newsletter …”, can increase the success rate. You could also add a little guide that explains to users how to add your address in the most common mail user agents (I created a little tool you can use for your German speaking audience: Finally, a vCard may also be offered for easy saving in desktop clients.
  5. “Look into junk”: Sensitize users to the problem that emails of new and previously unknown senders sometimes are mistakenly filtered out into the spam folder, where they are possibly overlooked. So, if the confirmation email doesn’t arrive in one or two minutes, the user should have a look there.
  6. Resend-button/Support: Provide the user with an option to resend the checkmail in case it can’t be found at all after some minutes. In addition, a “contact me” link or “does not work?” button can help detecting potential technical or usability related problems.
  7. Subject line: Make sure to use a meaningful and action-oriented subject line for your checkmail. A good example would be “Please confirm your subscription”, a bad one “Subscription confirmation” (see this test). The latter subject line is even misleading because it hardly gives the impression that another step is necessary.
  8. Sender name: The sender name is often sighted first in the inbox. Therefore, it should provide immediate recognition. Use your brand or your surname or whatever other identifier might provide a great recall value. Keep in mind that not only the subject line but also the sender name will be truncated after a certain number of characters. “Newsletter” would be a bad choice. Use “ Newsletter” instead.
  9. Confirmation link: The user should be able to see the confirmation link in the checkmail without any need to scroll (above-the-fold). It should stand out in the preview pane (see these two attention maps). And don’t let it get too long. Otherwise, there is a risk that lines break within links so that – in some email clients – they won’t work any longer. In any case the user should be given an appropriate help, such as “If the link doesn’t work, please copy and paste it into your browser’s address bar”.
  10. Keep it short: Focus primarily on the click in your checkmail copy. In addition, the email should also contain (1) information about to what exactly the user gives his consent (newsletter content, frequency, …), (2) a little sorry for those who received the email unwanted plus a note that any personal data will be automatically deleted in X hours when no confirmation is registered, (3) a link to the privacy policy, and (4) last but not least some contact details.
  11. High priority: The increase the visibility of your checkmail in the recipient’s inbox, you could try setting the priority header field to “urgent”. Most mail user agents place a red exclamation mark or something similar next to such an email so that it stands out.
  12. Email format: Basicially, there can be no objection in principle to send the checkmail in multipart format. However, if problems are suspected in deliverability, try switching to plain text.

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2 Responses to Double opt-in – 12 setup-tips to get a maximum outcome [2/2]

  1. Pingback: Subscriber Feedback: Learnings from Unsubscribe Reasons

  2. I came to this page by writing “double opt in rate” by using the quotes to Google. I was searching of how much lead would I lose by using double opt-in, and you said that it is around 40%… I really get critical infos from this post. Thanks.

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