Double opt-in is a verification method that triggers after you submit your email ID. Once you do this, you are also required to go to your mail box and click on a confirmation link to verify your email. It is a common practice by website owners to have a double opt-in for their email lists.
The primary reason why double opt-in is commonly used is to avoid spam or fake email IDs. This is a quick way to confirm the legitimacy of your user’s email ID. It is also to be noted that most services allow the user to continue using their service even without confirming their emails.
Although double opt-in is not a mandatory requirement, but it is best to have it owing to the benefits the feature offers. Having this will also ensure that your email deliverability rates are high and hard bounces are low.
In email marketing tools, the complete experience of double opt-in can be customized based on the user journey and your brand guidelines.