Abusive subscriber complaints occur when a subscriber marks a large number of messages as spam against a particular sender in a short period of time.
Typical causes of this behavior include:
- Sending frequent, unsolicited bulk email (spam) to a subscriber that did not give their consent.
- A breakdown in the complaint handling process where complaining subscribers are not added to a suppression list.
- A breakdown in the unsubscribe process where unsubscribe requests are not honored.
- A subscriber returning from vacation or logging in to their email account after an extended absence and finding an excessive number of emails in their inbox.
- The lack of a global unsubscribe option. A subscriber may believe they unsubscribed from all emails related to a specific sender but were only unsubscribed from a specific email stream or brand. Continually receiving emails after unsubscribing results in that subscriber marking all messages as spam in an attempt to stop receiving additional email.
Mailbox provider impact
Most mailbox providers, including Microsoft, (Outlook.com, Hotmail) and Comcast, register one complaint as one complaint, regardless of the frequency from a specific subscriber. So abusive subscriber complaints count directly against your complaint rate and factor into your sending reputation.
Gmail is the exception and counts one complaint per person per hour for a particular sender. For example, if a subscriber complained about 20 emails from a particular sender within one hour, the sender's IP and domain only incur one complaint. Although abusive subscriber complaints don’t have as big of an impact to your sending reputation at Gmail, complaints in general are a main factor in Gmail’s filtering decisions and should be kept to a minimum.
Validity Certification receives complaint data feeds directly from participating mailbox providers and uses the data to measure against compliance thresholds. The mailbox provider complaint data does not identify or separate complaints from abusive subscribers, so senders receiving abusive subscriber complaints are still required to meet Certification compliance thresholds.
While abusive subscriber complaints can’t always be prevented, following best practices and ensuring complaint and unsubscribe processes are working properly can reduce the risk of this happening to your email program. Should this behavior persist from specific subscribers, be sure they are globally suppressed from all future messages (unless sending to them is required by law) and ensure your list acquisition and list hygiene processes are following best practice guidelines.