Newsletter (mailing list, subscription form)


A newsletter signup is a guided navigation that aimed to subscribe a user to a newsletter.


There is actually two kinds of process:

Single opt-in

known also as unverified opt in

Single opt-in means that a person only has to enter their e-mail address, click subscribe, and that’s it. They are now subscribed to the list. (Yes, there is nothing stopping your from entering someone else’s e-mail address.)

Single opt-in enhance:

  • the email bomb effect. 'email bomb' services will sign a target email up for 1000s of 'single opt in' newsletters.
  • known also as the revenge-spam: someone takes your email and submits it to every default form they can find automatically, and then your inbox is flooded with ostensibly legitimate email that you have to manually unsubscribe from, for each individual list.

Double opt-in

Double opt-in confirmation refers to a workflow. Contacts who sign up will be placed into an Awaiting Confirmation status until they click on a link in a confirmation email.

It was known as:

  • confirmed opt in
  • or verified opt in

A single email is send to the email address entered on the subscription form with a clickable link to confirm twice the subscription. If there is no confirmation, the email is not added to the newsletter.

It verifies that the owner of the submitted e-mail address also intended to subscribe.

It's the only way to ensure the correct email address is added to the list, and the subscriber genuinely wants to receive emails from you.

double opt-in is necessary in the European Union as a proof of consent under GDPR and expressly required in Germany.

GDPR requires consent from the data subject to process personal data. An email address is personal data under GDPR. You can't guarantee consent with single opt-in.


  • Newsletters confirmation
Don’t forget to confirm by clicking on the button – or you won’t get the newsletter.

We do this final check to prevent people from subscribing you without your permission.
  • Account confirmation

Example of process

Call to Action


  • Yes, I would like to subscribe to email updates from xxx. I know it’s easy to unsubscribe if I ever change my mind.
  • Send me the newsletter. I expressly agree to receive the newsletter and know that I can easily unsubscribe at any time. This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Email Validation

Ensure that the email are valid (no fake sign-ups or old addresses)

see Email - Address Validation


Take measure against fake sign-up

  • The best measure is to load you form via javascript
  • You can also add a text field posing a simple question which only a human would answer naturally. Make the question relevant to your niche
    • Example: What do you want to learn most about computer science ?

Thank you email

Add to contact

If your subscriber has added you to their contact list or regularly opens your emails in which case their email client (Gmail, Yahoo, etc.) will know that you are a trusted source for that person.

You can encourage subscribers to add the newsletters sender to their contacts

  • on the thank you page
  • in the opt-in or introductory email


Where the link is a vcard link https://hostname/vcard

EMAIL:[email protected]

What when ?

Double Subscription

When a visitor subscribes twice, there is two approaches:

  • sending again the confirmation email because:
    • it's what the visitor expects (less friction)
    • of privacy and security concerns (nobody should know who is subscribed)
  • or showing a You're already subscribed error message (The update link sends an email with a token)

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