diff --git a/Readme.md b/Readme.md
index d36bacf0c619fc7956a7dfb9a40f4ae21fef3923..f70291419dcb666393dd066c97efa755a0426da4 100644
--- a/Readme.md
+++ b/Readme.md
@@ -39,7 +39,7 @@ graph LR
 
 ## Enable sending mails
 
-You need to add `sympa_rewrite` and `sympa_transport`  files to `sympa/shared/` directory:
+You need to add `sympa_rewrite`, `custom_rewrites` and `sympa_transport`  files to `sympa/shared/` directory:
 
 Example of a `sympa_rewrite` file:
 
@@ -49,6 +49,8 @@ Example of a `sympa_rewrite` file:
 /(.+)-owner@(.+)/	$1+owner@$2
 ```
 
+`custom_rewrites` can be empty, it should be used if you need to add someother aliases
+
 Example of a `sympa_transport` file, for each domain you have Sympa providing mailing lists:
 
 ```
diff --git a/docker/postfix/etc/postfix/main.cf.append b/docker/postfix/etc/postfix/main.cf.append
index fd7c4fefa1848e0fc75559acf87b196a86f355b7..7233a79a4958532800210cc4da6a28352764d868 100644
--- a/docker/postfix/etc/postfix/main.cf.append
+++ b/docker/postfix/etc/postfix/main.cf.append
@@ -13,6 +13,7 @@ virtual_mailbox_base = /tmp
 virtual_alias_maps =
   regexp:/etc/postfix/global_alias
   regexp:/etc/sympa/shared/sympa_rewrite
+  regexp:/etc/sympa/shared/custom_rewrites
 transport_maps =
   regexp:/etc/sympa/shared/sympa_transport