Since my hosting provider (A2 Hosting) does not provide support for my subscription plan for sending e-mails using an external SMTP service, I am short on options and cannot use the Dokuwiki's SMTP pluging.
So I studied the Bureaucracy plugin documentation and found that I can use an Action in Script Mode.
Basically I need to send the Bureaucracy form that an user has filled, via e-mail using the MailGun API service with curl.
MailGun provided me with the following example for using Curl:
curl -s --user 'api:YOUR_API_KEY' \
https://api.mailgun.net/v3/YOUR_DOMAIN_NAME/messages \
-F from='Excited User <mailgun@YOUR_DOMAIN_NAME>' \
-F to=YOU@YOUR_DOMAIN_NAME \
-F to=bar@example.com \
-F subject='Hello' \
-F text='Testing some Mailgun awesomeness!
Can someone please help me to write a simple Bureaucracy action script to perform this task, as I am inexperienced with the PHP lanquage.