All email that is sent from APSIS One allows the recipient to unsubscribe and opt-out of your communications in several ways:
The unsubscribe link in the email's body
The list-unsubscribe header's http-link
The list-unsubscribe header's mailto-link
The one click unsubscribe header
If the unsubscribe link in the email's body is connected to your CRM integration, then your consent list will be updated when synced with your lists in APSIS One.
Additionally, if you are handing subscriptions and unsubscribes in a separate system, then its important to constantly sync (both fetch and update) from APSIS One.
We always recommend that you treat the consent data in APSIS One as your primary data, to ensure GDPR compliancy.
It is also possible to unsubscribe via the APSIS One API or UI, and take that source of unsubscribe into consideration for all types of unsubscribe. Soon it will be possible to track unsubscribes via an external source with an Unsubscribe Event, including the source.
Using an unsubscribe link in the body of an email to redirect a recipient to an unsubscribe form is a common way to collect data on why subscribers want to opt-out of communications.
While an unsubscribe form should never be a requirement, if you choose to redirect to a form, it's important to bear in mind that the process should be quick and easy for your subscriber. A difficult unsubscribe process results in lower engagement and spam complaints.
Having a simple unsubscribe process is essential to consent list hygiene maintenance. When subscriber's decide to opt-out of your communications, your email engagement will increase, which will have a positive effect on inbox placement.
To read more about Consent Management, head to this article.