P7S file is a email message secured with digital signature. Digital signature guarantees that the file was not modified in transit and both sender and recipient are who they claim to be. Digital signature thus precludes possibility of the message being tampered with by a third-party if captured.
Email messages in P7S files are digitally signed using PKCS #7 (Public-Key Cryptography Standard) technology, and to open such message user needs to use email client that supports this standard. Most email applications recognize digital signatures, but some don’t. In the latter case P7S file will be listed as attachment with smime.P7S filename.
We hope we helped you solve the problem with the P7S file. If you do not know where you can download the application from our list, click on the link (which is the name of the program) - you will find more information there on the location where to download the secure setup version of the required application.
There can be more reasons which determine that you are not able to open the P7S file (apart from the lack of the proper application installed).
First - the P7S file may be incorrectly associated with the application installed to support it. In this case, you need to change this association by yourself. To do this, right-click on the P7S file that you want to edit, click "Open with" and then select the program from the list that you have installed. After this operation, the problems with opening the P7S file should be solved.
Second - the file you want to open can simply be damaged. Then, the best solution is to find a new version of given file, or download it again from the same source as before (maybe for some reason in the previous session the download of the P7S file has not been completed and it cannot be opened properly).
If you have additional information about the P7S file, we will be grateful if you share it with our users. To do this, use the form here and send us your information on P7S file.