What are the Solve labels in Gmail that look like #Solve360/{workgroupName} for?

When you apply this label to a message in your Google Apps mail, it will link that message to Solve. It is shared with the other users in the respective workgroup and it will be eligible to be linked to contacts, companies and project blogs in that workgroup. For more information take a look at our blog post: Automatically link Gmail messages to the CRM.