File Extension Database

Open P7M File

P7M file extension is used to denote a digitally signed and encrypted E-Mail. Both the E-Mail message itself and any attachments are added to the P7M envelope, which can only be opened by clients with the appropriate key.

P7M files are an implementation of the Secure/Multipurpose Internet Mail Extension (S/MIME) standard which supports public key encryption. S/MIME provides essentially two cryptographic services which can be used by E-Mail applications. The first is digital signatures, which can be used to authenticate a message, check its integrity and prove its origin or source. The second is encryption, which is used to ensure that data remains both private and secure, even if an E-Mail is intercepted by a third-party.

As P7M files are encrypted, it is not possible open P7M file to extract the contents without the appropriate software and decryption key. E-Mail applications with S/MIME support can be configured to automatically retrieve the necessary key to decrypt received P7M files and display the resultant message as an ordinary E-Mail. However, clients without support, such as web-based E-Mail services, will simply show the encrypted P7M E-Mail as an attachment.

Encryption is utilised by P7M files to ensure data privacy even if the E-Mail was accidentally sent to the wrong address or was intercepted during transmission. However, this has the disadvantage that anti-virus software is unable to detect malware, as it will not be able to decrypt the E-Mail once it has been created. Therefore, any attachments received in a P7M file should be checked prior to opening, even if they are from a known and trusted source.

You can open P7M files in any E-Mail client that supports S/MIME provided that the necessary public key is available. You can open P7M files using other applications such as Cryptigo p7mViewer, which is designed specifically for opening signed and encrypted E-Mails.

Typical P7M mime types:

application/pkcs7-mime

Frequently associated Windows objects:

P7MFile

How Can I Open P7M File on Windows

We researched and learned that the best way to open P7M file is to find a P7M file in question in Windows OS File Explorer and double click on it to launch the corresponding application.
If a P7M file is not opened in an application and you instead get a "Windows can't open a file" error message you should try looking for an application which can open the file in question.
If you know the application which can open P7M file then run it and see if there is a File->Open main menu option in the application.
If you don't know the application which function as P7M file opener then try to search online for "P7M viewer", "application to open P7M file" or "open P7M file" queries in the search engine you like.
Install the application you found and check if it can open P7M file

How Can I Open P7M File on Mac OS

We recommend to find a P7M file in question in Mac OS Finder and double click on it to launch the corresponding application.
If a P7M file is not opened in a Mac OS application and you instead get a "There is no application set to open the file" error message you can click on "Search App Store" in the error dialog and Mac OS will show you applications compatible with P7M file.
If you know the Mac OS application which can work as P7M file opener you can choose the "Choose Application..." option in the error box to associate the file extension and open P7M file in it.
If you don't know the application which can open P7M file then try to search for "P7M viewer", "application to open P7M file" or "read P7M file" queries in the online search engine you like.
Install the application you found and check if it can read P7M file

How Can I Open P7M File on Android

If you downloaded a P7M file on Android device you can open it by following steps below:

In the Android apps list on your Android device find "My Files" or "File manager" app and tap to start it.
Tap on "Downloads" folder inside the app.
You should see your downloaded P7M file in that folder.
Tap on the file. If Android device supports opening the file you downloaded it will open in the corresponding app.
If file does not open you can look for the corresponding app that can open the file by searching Android App Store for the "P7M".
If you cannot open the file with the apps from Android App Store it is possible that the file could only be opened on desktop platforms such as Windows or Mac OS. Try searching for "P7M viewer", "P7M file reader" online and see if any desktop applications can open it.
It is also possible that the file you downloaded is outdated and is no longer supported.

How to Open P7M File on iPhone or iPad

To open P7M File on iOS device follow steps below:

We advies to open Files app on your iPhone or iPad device. You can find it by swiping down on the home screen and typing "Files" in the search bar.
Tap on the Downloads folder on the Files app home screen.
You will see all files that you recently downloaded. Tap on the P7M file to view it.
If you have the right app that can open it it will automatically launch and open your file.
If you don't have the app which can open it you need to serch Apple app store for "P7M". This way you can find apps which can open P7M files.
If this doesn't help it is possible that your file could be opened only by the desktop application. To find an app which can open it on desktop look for "P7M viewer" or "P7M file" online in your favorite search engine.