Autoresponders: Single Opt-in vs. Double Opt-in

As an online business owner, one of the most valuable investments in web technology you can make is choosing an email service provider. They provide a service that can help you to put all of your email marketing, subscriber acquisition and follow up on automatic pilot.

Most email service providers offer a variety of features and benefits. For the sake of this post we will focus on the autoresponder.

The autoresponder allows the list owner to send automatic messages once an event has taken place. For instance, once someone fills out a web form an autoresponder can automatically send an email message to the user. This can be a one time event or a sequence of events over time.

The implementation of an autoresponder can yield great benefits and profits doing business online. It does come with a bit of confusion, however.

One of the main sources of confusion seems to be whether or not to choose single opt-in or double opt-in. In this post we will look at the pros and cons of both methods.

Also, I’ll show you the one single mistake I made that got me banned from a top email service provider in less than 48 hours.

Opt-in Process

The word opt-in is short for “giving someone permission to add you to their email list”. You are giving them permission to communicate with you via email. This is the core of email marketing.

Often time, in exchange for your email address you are given a free product like an ebook, video training, digital download, etc.

That process of exchange is called the “Opt-in Process”. This can be a one or two step process. Hence the term Single Opt-in and Double Opt-in.

Single Opt-in

As seen in the mind map above with the single opt-in process the content is available immediately after the web form is filled out. Also, the person is immediately added to the owner’s email list. No further action is required. Here are some quick benefits and drawbacks from the single opt-in process.


  • True immediate access to content
  • Provides the shortest path for the prospect which means less work
  • Can be easier to implement


  • No email address verification
  • Can lead to more bounces (emails never getting delivered)
  • Normally have lower open rates

Double Opt-in

This method requires an extra step before the prospect is added to your list and the content is delivered. Double opt-ins require a confirmation link is clicked to ensure the correct email address was entered and to verify that emails can reach the prospect’s inbox (as well as strengthen privacy).

So the prospect fills out the form, click the verification link in their email, and is then added to the owner’s list and delivered the requested content. Here are some quick benefits and drawbacks from the double opt-in process.


  • Eliminates erroneous email addresses
  • Confirmed emails can lead to higher deliverability (the probability that your emails will actually reach your prospect’s inbox)
  • Confirmed emails can lead to higher open rates


  • Adds extra step for prospect to do
  • Prospects can end up in “dead zone”
  • Can take longer to implement

Double opt-ins introduce a new factor called the “dead zone”. The dead zone is where prospects end up that have filled out the web form but have NOT clicked the verification link in their email. While the prospect is in this zone they will not be able to receive any emails from your autoresponder. The only fix is for them to click the verification link.

Which Method Should You Use?

The answer to this question is content and audience. The greater your content the greater the chances your form will get filled with the correct information.

The main reason someone will not fill out your form (or will fill out your form with fake information) is due to a lack of trust. They’re on the fence. You simply have not done enough to prove that your content is worth the exchange or you are a trustworthy source. Trust can be established in many ways, providing great content is usually the quickest.

Your first goal should be creating killer content with clear benefits for your target audience.

Even with great content there is one deficiency with the single opt-in process. Typos. If someone accidentally enters in the incorrect email address there is no way for them to know right away. They will still get access to the content promised but will not receive any future emails from you. This puts the burden on the prospect instead of the list owner to ensure their email is correct. While using a double opt-in lets the auto responder do the email verification for you.

Your audience plays an important factor in which method to use as well. If your audience is mature to the internet and familiar with the opt-in process you could probably see much success with a single opt-in process. However, if your audience consists of newbies and people just starting out you may want to use double opt-in to ensure they don’t make a mistake.

Tip: Use your opt-in form as a filter to help you dictate if your content is valuable enough. If you are not getting opt-ins change your copy or offer. If you are getting opt-ins use it as proof that you are on the right track. Either way just having an opt-in form on your site is a good thing.

Check out a recent case study from email service provider MailChimp. Here’s what they found when running a split test on single opt-in vs. double opt-in.

My recommendation is double opt-in. Some may argue it’s an extra step, but it’s a well needed extra step. Especially since it increases open rates and deliverability. For me, the quality leads are more important than a huge list.

Which Autoresponder is the Best?

Choosing the best autoresponder is subjective at best. It depends on your business model and how you plan to implement your email marketing strategy.

I have taken the top, most widely used email service providers amongst internet marketers and online business owners for review here. They are Aweber, Mailchimp, iContact, and GetResponse.

My sole purpose was to focus on ease of implementation (design) and deliverability. Email templates were a factor but not a necessity for me. In my business I need to get a nice looking form up as fast as possible and make sure my emails are hitting inboxes.


Aweber and GetResponse are tied for this one. I swear using GetResponses form builder reminded me of Aweber’s with the exception of the placement of options. See below.

GetResponse has a nice visual ruler for resizing while Aweber uses a pixel width input. Getting a custom button designed is a bit easier in Aweber due to less options. You can accomplish the same (if not more) with GetResponse you just have a few more setting fields to customize.

Both services provide push buttons to insert fields like header, footer, powered by, privacy and more. Both interfaces are drag and drop so you can rearrange to your liking. Also, they both come with some very good templates to start you off with in case you are not tech savvy.

If beautiful, custom forms are something you value Aweber and GetResponse should be at the top of your list.

iContact’s and MailChimp’s custom form building process can be defined with one word. Horrible. While MailChimp offers a bit more options than iContact neither of them allow you to truly customize your form. Heck, you can’t even design a custom button from their form builder interface!

This may not be a deal breaker for some. I know a lot of people that like to use the “Plain Jane” forms as is. Others may be using a WordPress theme that allows you to customize the web form in your WordPress panel. Whatever the case, the design interface on these two leave a lot to be desired.

If customizing webforms is important in your business I would stay away from iContact and MailChimp.


Does your email reach an active inbox or does it get stuffed into the Spam folder? While there’s no way to guarantee 100% deliverability, some of these services get pretty close. King of all is Aweber. Out of the box Aweber successfully delivered emails to Hotmail, Yahoo, and Gmail without getting mistaken for spam.

iContact and GetResponse both had issues with Hotmail marking their emails as spam. MailChimp’s free version doesn’t allow you to actually implement an autoresponder so I didn’t test it.

I found the biggest difference between Aweber and the rest is that they have rapport with most ISPs which allows their emails to reach their intended destination. This is in part due to the fact that Aweber’s default settings use double opt-in and your email address from your own domain instead of a secondary like Gmail.

The reason this is important is because iContact and GetResponse let you configure your autoresponder however you like. If you don’t what information to use to increase deliverability then you will see low numbers.

For example, iContact emails were getting delivered to my Yahoo spam folder. Once I changed my “reply to” email address to my domain email instead of my Gmail, emails instantly started hitting my Yahoo inbox. A small detail with a great impact.

The winner here is Aweber.

In all fairness…

There are other factors outside of what I’ve addressed here that may move you towards one email service provider over another.

GetResponse’s customization was the deepest I’ve seen. Even allows the list owner to direct subscribers to a custom page once they unsubscribe. Think of this as a way to say “Thank you” on their way out. Very nice feature.

iContact is an excellent contact management system. You can easily import contacts from your desktop or from your iPhone. Reports are clear and easy to follow; and creating segmented lists are very straight forward.

MailChimp has great tracking and reporting as well. In fact, you can even integrate Google Analytics with your account for a deeper tracking experience.

Also, iContact and GetResponse have amazing html newsletter editors. Making newsletters from templates and customizing your own template was a breeze and very flexible.

Ultimately the choice will be yours. Every service offers a trial period where you can give it a test drive and see for yourself. I would advise, however, once you have made your choice to stick with it. Just like any other technology, there will always be the “next best feature” available on another platform once you’ve made a decision.

Price check

As far as price is concerned, not many of the service providers offer their pricing up front. You have to sign up for an account to see the different pricing tiers. While I won’t go over the specific pricing for every service, you can expect to pay between $20-$30 a month for approximately 500 subscribers.

This is a minimum fee to pay for the power that these email service providers give you and your business.

How I Got Banned

My horror story is with implementing an email campaign for a client. The client provided me with an Excel sheet of contacts they wanted to be able to send a newsletter out to. Since they had no previous service provider I gave them a quick summary of the available services.

Price was a factor so they chose iContact. At the time I believe it cost $15/mo for 250 subscribers. This would allow my client to be able to test the service for a minimum cost on a sizable audience.

Contacts were uploaded (single opt-in used so no verification email was sent to users being added), first email campaign was sent, and all was well. So well, in fact, that the client saw an immediate impact on attendance in their organization the following day.

Needless to say they were ready to send out another one.

A log in attempt 48 hours after the first email message was sent and I realized I no longer had access to the account. We tried everything from changing passwords to setting up new accounts. Nothing worked. Finally I called iContact service center and spoke with a representative.

The representative told me that the account was locked indefinitely due to high bounce back rates. Come to find out most the emails provided to me on the Excel sheet were incorrect, no longer being used, or simply reported the emails as spam since they never gave anybody permission to send them a newsletter.

The only way to unlock the account was to prove to iContact that my client would be implementing a verification process for every subscriber. In other words, they wanted to see a double opt-in process being implemented going forward for all new subscribers.

What I learned was two fold. Never trust anybody’s exported email list, and take extreme caution while adding subscribers manually using single opt-in lists.

In review, my personal preference is double opt-in. I have seen pretty strong numbers and don’t plan on changing anytime soon. Also, I decided to use Aweber and couldn’t have been happier. The interface took a bit to learn but now I see why they are looked at as one of the best in the market.

Do you use single or double opt-in in your business? Which method works best for you? Drop me a line in the comments area below. I’d love to hear your experience.

Chris Davis

About the Author

Chris is the founder of Automation Bridge and Host of the All Systems Go! podcast. He has helped marketing tech startups raise a collective amount of funding over $237 million is passionate about helping you do the same.

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2 responses to “Autoresponders: Single Opt-in vs. Double Opt-in”

  1. Christian Richardson Avatar

    Hello Chris.

    I would agree that double opt-in is the best.

    It prevents me from wasting time with people that

    aren’t genuinely interested and keeps the sytem efficient.

    1. Chris Davis Avatar
      Chris Davis

      Hey Christian…thanks for stopping by!

      You are absolutely correct with filtering out the “fake” leads. A lot of time email service providers will send from a more secure server only to emails that have been double-opt confirmed.