diff --git a/doc/install/installation.md b/doc/install/installation.md
index 73b5fbb0c33a053c161bf368f073cb4a388aa201..f3d21ac4482a789583cfe0ced1fd95efc8cb4f82 100644
--- a/doc/install/installation.md
+++ b/doc/install/installation.md
@@ -78,7 +78,7 @@ Is the system packaged Git too old? Remove it and compile from source.
 
     # When editing config/gitlab.yml (Step 5), change the git bin_path to /usr/local/bin/git
 
-**Note:** In order to receive mail notifications, make sure to install a mail server. By default, Debian is shipped with exim4 whereas Ubuntu does not ship with one. The recommended mail server is postfix and you can install it with:
+**Note:** In order to receive mail notifications, make sure to install a mail server. By default, Debian is shipped with exim4 but this [has problems](https://github.com/gitlabhq/gitlabhq/issues/4866#issuecomment-32726573) while Ubuntu does not ship with one. The recommended mail server is postfix and you can install it with:
 
     sudo apt-get install -y postfix