P7S - Digitally Signed Email Message are a common part of doing business over the web Signing receipts is not possible when you are operating over the web but the P7S - Digitally Signed Email Message system offer an efficient way for you to have your signature safely sent through email messaging. This file prevents unauthorized persons from reading your messages and fro getting your digital signature. These messages are encrypted, protecting the information within the message. The Mac and Outlook have the capacity to open this encrypted data. Many people worry about strangers getting into their emails and opening important mail intended for special eyes but the P7S - Digitally Signed Email Message protects, keeping privacy a main priority.