In Time Matters/Billing Matters 14 and 14.1, when you use the option to send a Billing Matters invoice via Email using default text for the Email message, the text loses all carriage returns. Also, only the first Email in a batch of selected Matters is related to a Contacts and a Matter.
My work-around is to avoid the option for a Default Email Message and instead complete each billing Email, one at a time, using a Formattable Clipboard. Billing Matters will generate all the billing Emails with a Subject (set in Billing Preferences on the Accounts Receivable tab) and a blank body. Opening each Email and applying a Formattable Clipboard does three things: (1) Fills in the body of the Email with carriage returns, and (2) Lets you manually relates the Email to the Contact and Matter; and (3) Allows the automatic use of the client's First Name via a linked field in the Formattable Clipboard.