Don’t let your BizTalk Message Box database grow significantly by accumulating suspended messages, put in place a monitoring mechanism to identify and resolve suspended messages as soon as possible. When you find a database integrity problem that is causing your databases to grow use the BizTalk Terminator to resolve this.
Maintaining the health of your BizTalk databases is vital for any BizTalk environment, specially when we are talking about the BizTalkMsgBoxDb, there are several reasons for the databases to grow like suspended messages that you should avoid and resolved quickly when they happen. You can also have some integrity problems identified by using the out of the box Monitor Job or by running a tool like the Message Box Viewer, in this cases you can run the BizTalk Terminator which is a tool provided by Microsoft to address these issues.
Read about the BizTalk Terminator