Mailgun for WordPress

• Testing the configuration fails when using the HTTP API

Your web server may not allow outbound HTTP connections. Set Use HTTP API to “No”, and fill out the configuration options to SMTP and test again.

• Testing the configuration fails when using SMTP

Your web server may not allow outbound SMTP connections on port 465 for secure connections or 587 for unsecured connections. Try changing Use Secure SMTP to “No” or “Yes” depending on your current configuration and testing again. If both fail, try setting Use HTTP API to “Yes” and testing again.

If you have to use SMTP and something is still going horribly wrong, enable debug mode in WordPress and also add the MG_DEBUG_SMTP constant to your wp-config.php, like so:

define( 'MG_DEBUG_SMTP', true );

• Can this be configured globally for WordPress Multisite?

Yes, using the following constants that can be placed in wp-config.php:

MAILGUN_REGION       Type: string   Choices: 'us' or 'eu'
     ex. define('MAILGUN_REGION', 'us');
MAILGUN_USEAPI       Type: boolean  Choices: '0' or '1' (0 = false/no)
MAILGUN_APIKEY       Type: string
MAILGUN_DOMAIN       Type: string
MAILGUN_USERNAME     Type: string
MAILGUN_PASSWORD     Type: string
MAILGUN_SECURE       Type: boolean  Choices: '0' or '1' (0 = false/no)
MAILGUN_SECTYPE      Type: string   Choices: 'ssl' or 'tls'
MAILGUN_FROM_NAME    Type: string
MAILGUN_FROM_ADDRESS Type: string
MAILGUN_TRACK_CLICKS Type: string Choices: 'yes' or 'no'
MAILGUN_TRACK_OPENS  Type: string Choices: 'yes' or 'no'

• What hooks are available for use with other plugins?

  mg_use_recipient_vars_syntax
  Mutates messages to use recipient variables syntax – see
  https://documentation.mailgun.com/user_manual.html#batch-sending for more info.

  Should accept a list of To addresses.

  Should only return true or false.

  mg_mutate_message_body
  Allows an external plugin to mutate the message body before sending.

  Should accept an array, $body.

  Should return a new array to replace $body.

  mg_mutate_attachments
  Allows an external plugin to mutate the attachments on the message before
  sending.

  Should accept an array, $attachments.

  Should return a new array to replace $attachments.

• What hooks are available for use with other plugins?

  mg_use_recipient_vars_syntax
  Mutates messages to use recipient variables syntax – see
  https://documentation.mailgun.com/en/latest/user_manual.html#batch-sending for more info.

  Should accept a list of To addresses.

  Should only return true or false.

  mg_mutate_message_body
  Allows an external plugin to mutate the message body before sending.

  Should accept an array, $body.

  Should return a new array to replace $body.

  mg_mutate_attachments
  Allows an external plugin to mutate the attachments on the message before
  sending.

  Should accept an array, $attachments.

  Should return a new array to replace $attachments.