Explicitely say that mails can be disabled (#64)

source/environment.html.md

@@ -27,6 +27,9 @@ The SMTP server to send mails can be configured with:
 - `MAIL_HELO_NAME`: the name sent during EHLO/HELO.
 - `MAIL_ADDRESS`: the address that emails will be sent from.
 
+For the moment, Plume only sends mail when you need to reset your password (and only from the web interface, `plm users reset-password` doesn't send anything).
+If you don't plan to use this feature, you can simply remove (or comment) the lines to configure the mail server in your `.env`.
+
 You can also change the logo you want to use for your instance in this file. Your logo should be in the `static` directory.
 To make Plume load it, you can use:
 

source/installation/config.html.md

@@ -33,6 +33,9 @@ BASE_URL=plu.me
 ROCKET_SECRET_KEY=
 
 # Mail settings
+# If you don't want to setup a mail server and/or address for plume
+# and don't plan to use the "password reset" feature,
+# you can comment these lines.
 MAIL_SERVER=smtp.example.org
 MAIL_USER=example
 MAIL_PASSWORD=123456