High complaint rate warning

If you've received a high complaint rate warning message, this means that your contacts are marking your email as spam.

We expect that you maintain a complaint rate below 0.1%. If your complaint rate for a survey increases beyond that point, you risk your email delivery being throttled. If the complaint rate continues to rise, your account will be suspended.

High complaint rate warning prevention

Apply the following best practices to the email invitation and reminders of your survey:

  • The contacts you are inviting gave you permission to email them (opt-in)
  • Your contact list is up-to-date
  • The name in the 'from'-field is recognizable for the recipient
  • The subject line does not contain any spam words
  • The email has recognizable design and branding
  • The contents and survey are relevant to the recipient
  • You have contact information at the bottom of your email including street address
  • You mention why the recipient is receiving this email (e.g., You receive this invitation because you visited Event X on October 1st)
  • You don't send reminders too quickly; give your contacts the time to respond.

Complaint rate calculation

Our system automatically tracks the number of complaints (recipients are marking your emails as spam) in a 'sliding time window'. If during this timeframe the number of complaints for your survey exceeds a certain percentage, the remaining email invitations or reminders that still need to go out are throttled. How long depends on the time it takes for the rolling complaint rate to drop under the percentage again.

Threshold

Email providers interpret a high complaint rate as a sign that your recipients don't want to receive the email invitations and reminders that you are sending to them. Many email providers block emails from servers if the complaint rate is too high. This affects deliverability for all of our users. To protect our reputation as a sender, we monitor this metric closely and take prompt action if the rate gets too high.

So it's very important to always use a correct and up-to-date contact list. Use double opt-in to ensure that the email addresses entered are correct and in use, and don't use any old email lists.