diff --git a/doc/deploying-a-server.md b/doc/deploying-a-server.md
index f0f95092931e6ab22a405fd6d6562f939c911146..fa9bedcbaf0e3b5476af9b68b8fcc68d7bb7583e 100644
--- a/doc/deploying-a-server.md
+++ b/doc/deploying-a-server.md
@@ -45,6 +45,8 @@ Make sure you read [getting started](getting-started-as-a-hoster.md) first.
   * Configure an arbitrarily long password, and save it in wordpress/login.txt in /data/domains/domain.com/wordpress/login.txt. The user will be logging in with IndieAuth, but it's good to make a not of which password you set.
   * Activate the IndieWeb plugins/themes/widget as per [Dockerfiles issue 40](https://github.com/indiehosters/dockerfiles/issues/40).
 
+* Make sure to edit the files in /data/runtime/postfix/ to set up email forwarding. Also, ask another indiehoster to add the same forwarding and act as a fallback MX.
+
 ### Adding a new website to your server
 * For each site you want to deploy on the server, e.g. example.com, do the following:
   * Does example.com already exist as a domain name?