During the initial synchronization with MailChimp, Recurly will automatically create any list fields it needs. If you delete a merge tag, Recurly will not recreate the tag. Below is a list of merge tags Recurly uses to submit subscriber data to MailChimp:
Account email address.
Account first name.
Account last name.
Account company name.
Subscription plan code, if the account is a subscriber.
Subscription plan name, if the account is a subscriber.
Yes if the subscriber is in the trial period of a subscription, otherwise No.
Yes if the subscriber has a subscription (free or paid), otherwise No.
Date the subscription started.