Send discount after confirming email

Site URL: http://vibemade.com/

Hi! We're starting our mailing list and would like to offer a discount code. I've been able to add it as part of both the thank you message and the email when people submit their email. However, the email that is automatically sent is asking people to confirm their email. After they click confirm, all they get is a default looking page just thanking them.

How can I send people a discount *after* they've confirmed their email joining the mailing list instead of before?

Thanks in advance!