After installing Soapbox Mailer, you might find that you're unable to successfully upload Leads to Salesforce without receiving the following error message.
"Record type unavailable - Cannot find default record type of the appropriate type."
This is typically because user's profile you're using for importing does not have a default Lead record type associated with it. Here's how you can update this.
1) Login to Salesforce
2) Go to Setup > Manage Users > Profiles
3) Select the profile used by the user doing the importing
4) Click the "Object Settings" link
5) Click the "Leads" link
6) Click the Edit button
7) Under the Lead: Record Types and Page Layout Assignments section, ensure that a Default Record Type is chosen, and click the Save button