如何回复 Mailgun 的一系列使用请求问题？

使用 Mailgun 要求必须向它们发送表单，然后回复它们提出的问题。本来觉得验证了信用卡就可以使用了……

这是它们提出的问题：
- What types of emails will you be sending - Transactional or Marketing? Please tell us briefly about how your business uses email.
- Where do you source your database of email addresses? Please provide any available links.
- Are all of your email addresses double-opt in? (This means that the user has requested your emails through sign-up and then confirmed via email that they want to receive your communication).
- What is your expected monthly volume of messages?
- Have you read our Email Best Practices document?

我是这样回答的：
I just want to send the user registration confirmation, email address is the customers provide, it is a one-time.
Less than 500 volume of messages.

然后支持又回复：

Thank you for contacting Mailgun support.
You want to provide the customers with registration confirmation for what? Is it for a website? Please provide the link. When the customers provide their email address, is there a set of terms they have to agree to?
Let us know if you have any questions.

请求一个比较完整的回答，能使对方满意。