To create a MailGun account and connect it to GivingTech, do the following:
Create a Mailgun account by clicking here.
Verify the domain that you're going to be emailing from.
Create an API key on this page. Click on "add sending key" and enter the name GivingTech.
You'll then see an API key. Copy it to your computer.
4. Head to this page in your GivingTech account. Enter your domain (ex. givingmail.org) and the API key.
5. Click the "Active" checkbox.
6. Click "Submit".
That's it - you're ready to email!