changed(brevo): use env vars for smtp relay address and port.

config/env.example.optional

@@ -122,6 +122,10 @@ MATOMO_IFRAME_URL="https://matomo.example.org/index.php?module=CoreAdminHome&act
 # DOLIST_NO_REPLY_EMAIL=""
 # DOLIST_API_KEY=""
 
+# SMTP Provider: SIB (Brevo)
+# SENDINBLUE_SMTP_ADDRESS=""
+# SENDINBLUE_SMTP_PORT=""
+
 # Ratio of emails sent using SendInBlue
 # When present, N % of emails will be sent using SendInBlue
 # (and the others using the default SMTP provider)

config/initializers/sendinblue.rb

@@ -10,9 +10,9 @@ if ENV.key?('SENDINBLUE_BALANCING_VALUE')
     ActionMailer::Base.sendinblue_settings = {
       user_name: Rails.application.secrets.sendinblue[:username],
       password: Rails.application.secrets.sendinblue[:smtp_key],
-      address: 'smtp-relay.brevo.com',
+      address: ENV.fetch("SENDINBLUE_SMTP_ADDRESS", "smtp-relay.brevo.com"),
       domain: 'smtp-relay.brevo.com',
-      port: '587',
+      port: ENV.fetch("SENDINBLUE_SMTP_PORT", "587"),
       authentication: :cram_md5
     }
   end