Similar to sending a text message to agents, you can now send custom text messages to clients! To do so, you will first have to purchase your own ISN SMS number. Here is an article to do that. http://help.inspectionsupport.net/en/articles/110320-purchase-your-own-sms-text-number
To start off, go to Clients/Agents, then click Clients. Find the client you are looking for, and click the Edit button.
From the client edit screen, click Send SMS.
You will then be able to type in a custom message and send it to the client.