# Deliverability

The measure of how many emails sent that reach their intended recipients without issue.

[Deliverability][] depends on many factors:

* Your [email security practices][secure]
* Your [sending reputation][rep]
* How you manage [voluntary recipient suppression][unsub]
* How other systems might [suppress your system as an email sender][bl]
* The [throughput capacity][bounce] of ISPs and recipient incoming email servers

To measure your delivery rate, divide the total number of emails delivered by the total number of emails sent.

Many factors influence email deliverability. To improve deliverability, follow these best practices:

* Build your sender reputation
* Secure your infrastructure
* Authenticate your mail streams
* Monitor your sending data
* Send wanted mail

## Related resources

* [Email Deliverability Guide](https://www.twilio.com/en-us/resource-center/email-deliverability-guide)

[bounce]: /docs/sendgrid/glossary/bounces

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

[secure]: /docs/sendgrid/glossary/domain-authentication

[bl]: /docs/sendgrid/glossary/blocklist

[unsub]: /docs/sendgrid/glossary/unsubscribes

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