> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lithoblocks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Mention a Slack user by email

> Resolve an email address to a Slack mention when sending through the connected workspace.

Use the dedicated mention placeholder when your application knows an email address but not a Slack user ID:

```text theme={null}
Please review this request, {{@user.email:alex@example.com}}.
```

The send pipeline resolves the email in the connected Slack workspace and produces Slack mention syntax when the lookup succeeds. An ordinary `{{email}}` placeholder only inserts text.

## Prerequisites and verification

The Slack installation needs `users:read` and `users:read.email`. The email must belong to a user in that workspace. Workspace policies, deactivated accounts, or a different login email can prevent resolution.

Send to a test channel and check that Slack displays the intended mention. Do not treat a browser preview as proof of a successful Slack lookup. Avoid relying on an unresolved address as a notification.

When the destination itself should be a DM, use `recipient_email` in the [send API](/guides/send-with-api); mentioning a person in a channel does not change the message destination.

[Connect Slack](/connecting-slack) · [Placeholders](/guides/templates-placeholders)