Signing the mails will ensure that they do not get filtered out by anti-spam of junk mail filtering programs. The recipient users would also be assured of their authenticity.
Another place where E-Lock S/MIME solution has been used is for application-to-application communication. Organizations like RosettaNet have defined extensive standards to automate the communication between disparate applications like Supply-chain, transport, procurement, dispatch and delivery. These standards use XML as the basic messaging format and define S/MIME as the communication mechanism.