Improve email config

Add specific auth options, specify sender address

config/environments/production.rb

@@ -64,11 +64,17 @@ Rails.application.configure do
   config.action_mailer.smtp_settings = {
     address: "mail.gandi.net",
     port: "587",
+    authentication: plain,
+    enable_starttls_auto: true,
     user_name: Rails.application.credentials.smtp[:username],
     password: Rails.application.credentials.smtp[:password]
   }
 
-  config.action_mailer.default_url_options = { host: "accounts.kosmos.org", protocol: "https" }
+  config.action_mailer.default_url_options = {
+    host: "accounts.kosmos.org",
+    protocol: "https",
+    from: "accounts@kosmos.org"
+  }
 
   # Ignore bad email addresses and do not raise email delivery errors.
   # Set this to true and configure the email server for immediate delivery to raise delivery errors.