If you'd like to see a list of all the custom fields, as well as any other Salesforce component used by Soapbox Mailer, just go to Setup > Installed Packages > Soapbox Mailer for Salesforce > View Components.
Happy emailing!
updated
If you'd like to see a list of all the custom fields, as well as any other Salesforce component used by Soapbox Mailer, just go to Setup > Installed Packages > Soapbox Mailer for Salesforce > View Components.
Happy emailing!