Need Wordpress contact form that will autorespond with custom login credentials

I need a Wordpress (v4.9.4 running child theme) contact form that autorespond to the user and will contain an email that includes a custom username, password and server URL. The username, password and server URL data will be manually maintained in the WP Admin page. These entries can't be reused so once one is used and sent, it needs to be marked as sent. Next request will grab the next available one and so on and so forth. As far as list maintenance, it can be edited manually through a csv or preferably through a page in the WP Admin. I also need an alert email to be sent when there are no more usernames that can be sent so we know to reload them. Suggested workflow; 1. User fills out contact form on website 2. User gets a confirmation page or message saying form has been received and they will received their trial information shortly and to contact <email> if not received within 15 minutes. 3. Wordpress looks up a username list and grab the next available entry (Not marked as used) and insert that data in the autoresponder email. It then marks that entry as used and also enters the contact name email address. If that is the last entry (No more unused entries) send an admin email saying that trial user accounts need to be added. 4. Send autoreponder email to user that contains a custom email body and also includes the username, password and server URL. I would also really like to log all SMTP functions. The log doesn't have to be accessible through the WP Admin but should be accessible from the server filesystem.