> For the complete documentation index, see [llms.txt](https://jotter.gitbook.io/red-team/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jotter.gitbook.io/red-team/network/common-protocols/smtp.md).

# SMTP

## SMTP

SMTP handles sending mail. While not an incredibly potent target, it can be used to enumerate valid usernames and send internal malicious emails if misconfigured.

**User Enumeration**

```
smtp-user-enum -M RCPT -D contoso.com -U users.list -t 10.129.203.12
```