In order to send a message, an influencer must belong to at least one of your campaigns. Once you have created a campaign, you can click the Discover Influencers button from the campaign screen, your dashboard or you can click the Discover Influencers link on the left menu bar. Within the Discover tool, click Add to Campaign on the specific influencer you want to contact. You can either click Send Pitch or click the envelope button to send a message, depending on which is applicable.
Note: There is a 3 message limit implemented within the transaction thread before the pitch has been accepted. The message limit will disappear once the pitch has been accepted and the transaction has kicked off.