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

# Sendmail

To add Guardian Mail.

Edit your [*sendmail.mc*](http://sendmail.mc) file (usually found in /etc/mail) and add the following:

```
FEATURE(`dnsbl',`<APIKEY>.combined.mail.abusix.zone',`"554 Rejected " $&{client_addr} " is listed by Guardian Mail see http://abusix.ai/search?q="$&{client_addr}')dnl
```

Replace \<APIKEY> with “**Your API key”** from your account in [app.abusix.com](http://app.abusix.com).

Compile [*sendmail.mc*](http://sendmail.mc) by running “*make*” in the same directory and then restart the Sendmail daemon.