Opening a P7S File

The P7S file type is primarily associated with Outlook.

P7S	File extension: P7S
	File type:	email signature/certificate

What is a P7S file?

P7S files mostly belong to Outlook by Microsoft. A P7S file is the signature or certificate of a message which is signed using Public-Key Cryptography Standards #7 (PKCS #7). This is also called the Cryptographic Message Syntax Standard. In some cases, a signed message, itself, is saved in a P7S file. It may contain encrypted data, digested data, signed data, or signed-and-enveloped data. PKCS #7 forms the basis for S/MIME (Secure/Multipurpose Internet Mail Extensions). Email clients such as Outlook, Mail, and Thunderbird can parse messages and message signatures/certificates saved in a P7S file.

How can I open a P7S file?

You need a suitable software like Outlook to open a P7S file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your P7S file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a P7S file directly in the browser:. Just drag the file onto this browser window and drop it.

Online P7S File Viewer

Choose your .p7s file to view

or drag and drop it here

Online File Viewer

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How to extract texts from P7S files or capture a screenshot to PDF, JPG, DOCX, TXT, ...

You can extract texts from P7S file or capture a preview screenshot using our online P7S file viewer:

To do so, click the "Choose your .p7s file to view" button above.
Your P7S file will then be displayed in the browser.
Now click on "Save as..." at the top of the page.
Then choose the file format (e.g. JPG, PDF, DOCX, TXT, ...) you want.
Download the converted file.

Programs that open and convert P7S files:

Outlook by Microsoft
See the previous paragraphs to learn more about the main application. P7S files are often referred to as Outlook encodeds because this type of file is primarily created or used by this software.
Mail (email signature/certificate) by Apple
Mail is the email client application of Apple operating systems such as macOS, iOS, and iPadOS. It can read messages and message signatures saved in P7S files. This file format is classified as Encoded. Related links: PKCS 7, PKCS, Introduction to Digital Signatures and PKCS #7
Thunderbird (email signature/certificate) by Mozilla
Thunderbird is an open source email client application for cross-platform desktop environments. It can read an email signature or message signed with PKCS #7 public data encryption method and saved in a P7S file. This file format is classified as Encoded. Related links: PKCS 7, PKCS, Introduction to Digital Signatures and PKCS #7

P7S file format:

The file format determines how the data is stored in the file. The first characters in a file identify the file format, for example, HTML files start with the bytes <html>. However, different programs can use the same file extension, and file extensions can be assigned incorrectly. Exact knowledge of the format is therefore important in order to solve problems occurring in files. Our evaluation of the P7S files is as follows:

The P7S file extension is quite widespread and contains well-defined data in an established structure that can be read by various programs. The file formats most commonly found in P7S files are:

90% of all P7S files are PKCS #7 Signature files, which are using the popular certificate file format. A digital certificate is a unique, digitally signed document which authoritatively identifies the identity of an individual or organization. Using public key cryptography, its authenticity can be verified to ensure that the software or website you are using is legitimate. The content consists of illegible binary data, which can only be read and interpreted by the associated programs. The average file size is 6 KB with most files being between 2 KB and 480 KB in size. The file type is very recent. smime.p7s is a typical file name. Files like these have the following tags: sarcini, caiet, docx, formulare, tender, restricted, annex, contract and anexa.
5% of all P7S files are based on the popular certificate file format. A digital certificate is a unique, digitally signed document which authoritatively identifies the identity of an individual or organization. Using public key cryptography, its authenticity can be verified to ensure that the software or website you are using is legitimate. The content consists of illegible binary data, which can only be read and interpreted by the associated programs. Most of these files are 98 KB to 3 MB in size. The following keywords are characteristic: PDF-1. These files are attributed to semnat, raspuns, solicitare, potvrzeni, letter, pentru, dpfdp and dali.

The remaining 5% of all P7S files are different files with different signatures, often e.g. Received. They are often associated with semnat, raspuns, clarificari, solicitare, propunere or xlsx. If you want to find out what your P7S file contains, drag and drop it onto this page.

Technical Data for P7S File Extension

File classification:

Encoded

Related files:

sig, 7ps, pkcs, p7m, p7, pdf, zip, p7b, sgn, sign, xml, pks, pkcs7, jpg, p7z, html, p7e, txt, s7p, eyp, msg, eml

Mime type:

application/pkcs7-signature, application/pkcs7-mime

The following listing is compiled from the database produced by the 'Associate This!' program, selected data from the main FILExt database and file extension information submitted by users.

ProgramID: P7SFile, FileType: PKCS #7 Signature, AppName: Crypto Shell Extensions
EXEFile: cryptext.dll

ProgramID: P7SFile
EXEFile: %SystemRoot%\system32\rundll32.exe cryptext.dll,CryptExtOpenPKCS7 %1

ProgramID: P7SFile
EXEFile: rundll32.exe cryptext.dll,CryptExtOpenPKCS7 %1

ProgramID: P7SFile
EXEFile: rundll32.exe %SystemRoot%\ServicePackFiles\i386\cryptext.dll,CryptExtOpenPKCS7 %1

ProgramID: P7SFile
EXEFile: %SystemRoot%\system32\\rundll32.exe cryptext.dll,CryptExtOpenPKCS7

Show all 5 listings To Top

a p7s email signature/certificate is a special file format by Microsoft and should only be edited and saved with the appropriate software.

How to solve problems with P7S files

Associate the P7S file extension with the correct application.
Update your software that should actually open email signature/certificates. Because only the current version supports the latest P7S file format. Search, therefore, e.g. on the Microsoft manufacturer website after an available Outlook update.
To make sure that your P7S file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .P7S file online - secure, fast, and no downloads needed.