A customer's email_status can have the following integer values:
0: reachable email address and not unsubscribed.
1: email address is empty (or null). This was set explicitly by the client/customer.
2: malformed address. Address does not conform to email address syntax.
3: unsubscribed. Email address is unsubscribed.
4: reported spam. Email address reported content as spam to their ISP.
5: hard bounce. Emails to this address have hard bounced.
17: address is @qq.com.
Zaius email campaign are sent to customers who are Reachable. Reachable is defined as email_status=0.
How email status changes
The email address is automatically validated whenever it is updated (either the first time it is received or when the address changes from a previous address). This will always put the customer in one of these states: 0, 1, 2, 17.
Email status can also be changed on the following events:
- event = email/action = unsubscribe. Email status set to 3
- event = email/action = spamreport. Email status set to 4
- event = email/action = hard_bounce. Email status set to 5
- event = email/action = (re)subscribe. Email status set to 0
Managing unsubscribe and resubscribe
There are two approaches to subscription management:
- Using the email service provider
- Using account preferences at the website/app level
Many email service providers provide a mechanism for customers to manage their subscription preferences. The ESP provides subscription management links where customers can opt-in and opt-out of emails. If a customer has unsubscribed then the ESP will suppress any sends to that customer. Zaius integrates with the ESP and receives unsubscribe events from the ESP and updates the customer's email status appropriately.
It is possible to combine these two approaches. However, Zaius does not inform the ESP of a customer resubscribing, thus even if a resubscribe event is sent, the email may still be suppressed by the ESP (if the user unsubscribed via the ESP).
Tencent, the owner of qq.com, has a very strict email frequency/rate policy, which the vast majority of ESPs are unable to accommodate. In order to preserve email reputation and deliverability, emails to qq.com addresses are suppressed.