> For the complete documentation index, see [llms.txt](https://docs.overleaf.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.overleaf.com/on-premises/configuration/overleaf-toolkit/email-delivery.md).
# Email delivery
Overleaf supports sending email through two methods: Simple Mail Transfer Protocol (SMTP) and [Amazon Simple Email Service (SES)](https://aws.amazon.com/ses/). SMTP can be used if you have an email server enabled on your localhost that is listening for local connections.
## Configuration
Email is configured using the following environmental variables.
#### Sender Configuration
| Name | Description |
| ----------------------------- | ----------------------------------------------------------------------------------------------------------- |
| `OVERLEAF_EMAIL_FROM_ADDRESS` | The from address e.g. ''
- Required: yes
|
| `OVERLEAF_EMAIL_REPLY_TO` | The reply to address e.g. `'noreply@mycompany.com'` |
#### SMTP
| Name | Description |
| --------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `OVERLEAF_EMAIL_SMTP_HOST` | The hostname or IP address to connect to. Needs to be accessible from the Docker container |
| `OVERLEAF_EMAIL_SMTP_PORT` | The port to connect to |
| `OVERLEAF_EMAIL_SMTP_SECURE` | If `true` the connection will use TLS when connecting to server. If `false` or not set, then TLS is used if server supports the `STARTTLS` extension. In most cases set this value to `true` if you are connecting to port `465`. For port `587` or `25` keep it `false` |
| `OVERLEAF_EMAIL_SMTP_USER` | The username that should be used to authenticate against the SMTP server |
| `OVERLEAF_EMAIL_SMTP_PASS` | The password associated with the SMTP username |
| `OVERLEAF_EMAIL_SMTP_TLS_REJECT_UNAUTH` | If `false` this would open a connection to TLS server with self-signed or invalid TLS certificate |
| `OVERLEAF_EMAIL_SMTP_IGNORE_TLS` | When `true` and `OVERLEAF_EMAIL_SMTP_SECURE` is `false` then TLS is not used even if the server supports `STARTTLS` extension |
| `OVERLEAF_EMAIL_SMTP_NAME` | Optional hostname for TLS validation if `OVERLEAF_EMAIL_SMTP_HOST` was set to an IP address, defaults to hostname of the machine. |
| `OVERLEAF_EMAIL_SMTP_LOGGER` | When `true` prints logging messages to `web.log`. |
#### Amazon SES SMTP interface
You can read more about using the Amazon SES SMTP interface to send email [here](https://docs.aws.amazon.com/ses/latest/dg/send-email-smtp.html).
| Name | Description |
| -------------------------- | ------------------------------------------------------------------------------------------ |
| `OVERLEAF_EMAIL_SMTP_HOST` | The hostname or IP address to connect to. Needs to be accessible from the Docker container |
| `OVERLEAF_EMAIL_SMTP_PORT` | The port to connect to |
| `OVERLEAF_EMAIL_SMTP_USER` | The username that should be used to authenticate against the SMTP server |
| `OVERLEAF_EMAIL_SMTP_PASS` | The password associated with the SMTP username |
#### Amazon SES API
You can read more about using the Amazon SES API to send email [here](https://docs.aws.amazon.com/ses/latest/dg/send-email-api.html).
| Name | Description |
| -------------------------------------- | ------------------------------------------- |
| `OVERLEAF_EMAIL_AWS_SES_ACCESS_KEY_ID` | If using AWS SES the access key |
| `OVERLEAF_EMAIL_AWS_SES_SECRET_KEY` | If using AWS SES the secret key |
| `OVERLEAF_EMAIL_AWS_SES_REGION` | If not set, the default region is US-EAST-1 |
#### AWS SES with Instance Roles
| Name | Description |
| ----------------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| `OVERLEAF_EMAIL_DRIVER` | When this is set to `ses`, the email system will use the SES API method and rely on the configured instance roles to send email. |
#### Customisation
| Name | Description |
| ------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `OVERLEAF_CUSTOM_EMAIL_FOOTER` | Custom HTML which is appended to all emails. e.g.
Example: "\This system is run by department x \
\