diff --git a/documentation/administrators b/documentation/administrators
index 083f8e3..7f53a04 100644
--- a/documentation/administrators
+++ b/documentation/administrators
@@ -165,7 +165,7 @@ system user "git"
 
 3. Create the file /home/git/.forward with the content:
 
-    |/home/git/clif/emails.py
+    "| SERVER_DOMAIN= REPOSITORIES_PATH= /home/git/clif/emails.py"
 
 This is a sendmail file (also used by postfix) for deciding how incoming messages
 shall be delivered to the the system user. For our purposes, we instruct postfix
diff --git a/emails.py b/emails.py
index 334b6f3..fea03fb 100755
--- a/emails.py
+++ b/emails.py
@@ -22,11 +22,11 @@ import sys
 
 # The "domain" part in address@domain for the mailing lists.
 # All emails addressed to another domain will be ignored.
-SERVER_DOMAIN = None
+SERVER_DOMAIN = os.environ.get('SERVER_DOMAIN')
 
 # The folder containing the git repositories.
 # If using Gitolite, this is the Gitolite's "repositories" folder
-REPOSITORIES_PATH = None
+REPOSITORIES_PATH = os.environ.get('REPOSITORIES_PATH')
 
 # Level    | Numeric value
 # ---------|--------------