# Complaint

*Reputation*. A record of an email recipient reporting an email message as [spam][].

When a recipient makes a [spam report][], this counts as a complaint.

To calculate your complaint rate, divide the total number of email messages the received by the number of complaints that recipients reported.

As the number of complaints increase, your [reputation][ers] drops, then your [email deliverability][] drops.

To learn more, see the Twilio [Email Infrastructure Guide][].

[Email Infrastructure Guide]: https://www.twilio.com/en-us/resource-center/the-email-infrastructure-guide-build-it-or-buy-it

[email deliverability]: /docs/sendgrid/glossary/deliverability

[spam]: /docs/sendgrid/glossary/spam

[spam report]: /docs/sendgrid/glossary/spam-reports

[ers]: /docs/sendgrid/glossary/email-reputation-score