Extend mail config and help. #1487

.env.docker

@@ -50,6 +50,7 @@ COOKIE_DOMAIN=
 COOKIE_SECURE=false
 
 # If you want Firefly III to mail you, update these settings
+# For instructions, see: https://firefly-iii.readthedocs.io/en/latest/installation/mail.html
 MAIL_DRIVER=${MAIL_DRIVER}
 MAIL_HOST=${MAIL_HOST}
 MAIL_PORT=${MAIL_PORT}
@@ -58,6 +59,12 @@ MAIL_USERNAME=${MAIL_USERNAME}
 MAIL_PASSWORD=${MAIL_PASSWORD}
 MAIL_ENCRYPTION=${MAIL_ENCRYPTION}
 
+# Other mail drivers:
+MAILGUN_DOMAIN=${MAILGUN_DOMAIN}
+MAILGUN_SECRET=${MAILGUN_SECRET}
+MANDRILL_SECRET=${MANDRILL_SECRET}
+SPARKPOST_SECRET=${SPARKPOST_SECRET}
+
 # Firefly III can send you the following messages
 SEND_REGISTRATION_MAIL=true
 SEND_ERROR_MESSAGE=false