SMTP Relay

HOST     smtp.inbox.onesourcesoft.com
PORT     587 (STARTTLS) or 465 (TLS)
USER     apikey
PASS     <your INBOX_API_KEY>
AUTH     LOGIN, PLAIN, CRAM-MD5
TLS      Required (1.2 or 1.3 only)

define('WPMS_ON', true);
define('WPMS_SMTP_HOST', 'smtp.inbox.onesourcesoft.com');
define('WPMS_SMTP_PORT', 587);
define('WPMS_SSL', 'tls');
define('WPMS_SMTP_AUTH', true);
define('WPMS_SMTP_USER', 'apikey');
define('WPMS_SMTP_PASS', 'YOUR_INBOX_API_KEY');

# config/environments/production.rb
config.action_mailer.smtp_settings = {
  address:        'smtp.inbox.onesourcesoft.com',
  port:           587,
  user_name:      'apikey',
  password:       ENV['INBOX_API_KEY'],
  authentication: :plain,
  enable_starttls_auto: true,
}

Use X-INBOX-Category to tag mail. The dashboard splits stats by tag automatically. X-INBOX-Custom-Args accepts a JSON object that is preserved on every event for that message.

SMTP pipelining and CHUNKING are supported. You can send thousands of RCPT TOs in a single session. Per-tenant rate limits apply at the connection level.