The File Extensions Database

.P7S File Extension

  • Category: Text Files

What is an .P7S file?

.P7S is Digitally Signed Email Message

A P7S file is an email message that includes a digital signature. It can be used for sending secure emails that can only be viewed by the intended recipient. P7S files verify that the email is from who it claims to be from and that the email has not been modified in transit.

Most email applications, such as Microsoft Outlook, Apple Mail, and Mozilla Thunderbird, support digital signatures. However, if an email program does not handle digital signatures, a P7S file may appear as an attachment (smime.p7s) to the email message.

NOTE: Email programs that use P7S files use PKCS (Public-Key Cryptography Standard) #7 to sign email messages.

Programs that open Digitally Signed Email Message
Microsoft Outlook 2016
Mozilla Thunderbird
Apple Mail
Mozilla Thunderbird
Mozilla Thunderbird

How to solve problems with P7S files

  • Associate the P7S file extension with the correct application. On :
    Windows: Right click on any P7S file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.P7S files". Mac: Right click (or Ctrl-click) the P7S file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .P7S is Digitally Signed Email Message. Because only the current version supports the latest P7S file format. Search, therefore, e.g. on the N/A manufacturer website after an available .P7S is Digitally Signed Email Message update.
  • To make sure that your P7S file is not corrupted or virus-infected, get the file again and scan it with antivirus software.