To “opt” is to make a choice. In the world of email, ISPs like Google, Yahoo, and Microsoft protect their users by expecting senders to offer and respect a subscriber’s freedom to choose. In order to be a white hat sender, you need to ensure that you’re sending wanted mail to those who’ve asked to hear from you. There are a couple of ways (single opt-in and confirmed opt-in) for your users to opt into your email program, so we’ll examine them both in this post.

Single opt-in

Let’s first look at the term, “opt in,” AKA the “single opt-in.” In regard to email, opt-in is the subscriber giving a sender the permission to email them. This permission should explicitly state what type of email is wanted and how often it is expected. This is a good first step when adding new recipients to your list and is preferred over scraping, purchasing, or renting email lists, but there are still vulnerabilities to this practice.

Solely relying on a single opt-in does not protect you from typo addresses, invalid addresses, or unengaged users. High invalid address rates and low engagement rates are two of a multitude of indicators ISPs use to decide whether to inbox, bulk, or outright block a particular sender’s mail stream. ISPs are continually tightening the protection of their users and are expecting stronger relationships between the receiver and sender.

Confirmed opt-in

Into play comes the confirmed opt-in (COI), AKA “double opt-in.” This industry recommended practice is a gold standard among the best senders and ISPs. The name says it all; once a subscriber has opted into a sender’s mail stream, be polite and CONFIRM their consent. It’s the email way of a sender saying, “Hey, I know that you gave me your address to send to, but I just want to double check that you really want to receive what I’m sending.” It’s personable, polite, and as a bonus, incredibly productive.

How confirmed opt-in works

After initially opting in through a subscription channel (web sign-up form, in person sign up, referral, etc…) the sender verifies the subscriber’s interest. In short, redirect the subscriber back to their inbox where a confirmation email has been sent where they can verify the address.

When most effective, this email contains a call-to-action that say’s something such as, “Click Here To Confirm Your Address!”. The users who engage and click are assumed to be real subscribers who are interested in receiving your content. This is great because ISPs also see that your users are engaging in your mail (thumbs up from the ISPs). Once users have confirmed their address, it’s best to redirect them to their account or email preferences where they can better adjust their interests with the incoming mail.

After email expectations are set, the new user enters the welcome series and a consistent incoming mail stream. Users who don’t confirm their email address are removed from the mailing list and fall under the category of either invalid, spam trap, mistyped, or simply disinterested. None of these categories are worth your time or effort. Let them go and focus on users who show signs of sticking around. Correctly implementing a confirmed opt-in cuts down on bounces and ensures engagement rates are higher and more accurate.

Putting it all together

The objective is to send wanted email, so remember, confirmed opt-in is the gold standard and ISP expectations will always be moving toward explicit relationships like it. ISPs care about their users’ choices and preferences. The more options you, as a sender, can present to a recipient, the better off you’ll be in the eyes of the ISPs. Not establishing an understood relationship will surely doom the delivery of any sender.
To learn more about setting proper expectations with your recipients, check out our webcast with our delivery consultant, Luke Martinez, Great Expectations: Setting Your Email Marketing Up for Success.



Taylor is an Associate Email Delivery Consultant for SendGrid. Alongside the delivery team, Taylor takes pride in showcasing deliverability insight as well as whitehat know-how to the world.