P7M File Extension

What is P7M file?

Files in the P7M format are responsible for storing encrypted (or signed digitally) email messages. In such file, there are stored the content and the attachment.

Access to encrypted messages

P7M files have one main purpose – protection of information contained within a message against an unauthorised access of third persons. In order to read an encrypted email it is required to possess a private key, adequate to the public key of received message. Private key is always the same, so that the target recipient has an easy access to each new message.

Additional information:

• P7M files are often used to send fragile, protected data within medicine, financial or business industries;
• P7M files use the Secure/Multipurpose Internet Mail Extension standard (S/MIME) cyphering method;
• messages encrypted in P7M files usually occur as smime.p7m

Such email messages provide only information within a header with an empty content field. Text of the encrypted message is contained within the encrypted attachment.

Programs which support P7M file extension

The following list contains programs grouped by 2 operating systems that support P7M files. P7M files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.

Updated: 07/26/2023

How to open file with P7M extension?

Problems with accessing P7M may be due to various reasons. Fortunately, most common problems with P7M files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The following is a list of guidelines that will help you identify and solve file-related problems.

Step 1. Install Eudora software

Problems with opening and working with P7M files are most probably having to do with no proper software compatible with P7M files being present on your machine. This issue can be addressed by downloading and installing Eudora or different compatible program, such as Apple Keychain Access. On the top of the page a list that contains all programs grouped based on operating systems supported can be found. One of the most risk-free method of downloading software is using links provided by official distributors. Visit Eudora website and download the installer.

Step 2. Update Eudora to the latest version

If you already have Eudora installed on your systems and P7M files are still not opened properly, check if you have the latest version of the software. Sometimes software developers introduce new formats in place of that already supports along with newer versions of their applications. This can be one of the causes why P7M files are not compatible with Eudora. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using Eudora.

Step 3. Set the default application to open P7M files to Eudora

If you have the latest version of Eudora installed and the problem persists, select it as the default program to be used to manage P7M on your device. The next step should pose no problems. The procedure is straightforward and largely system-independent

Change the default application in Windows

• Clicking the P7M with right mouse button will bring a menu from which you should select the Open with option
• Next, select the Choose another app option and then using More apps open the list of available applications
• To finalize the process, select Look for another app on this PC entry and using the file explorer select the Eudora installation folder. Confirm by checking Always use this app to open P7M files box and clicking OK button.

Change the default application in Mac OS

• From the drop-down menu, accessed by clicking the file with P7M extension, select Information
• Proceed to the Open with section. If its closed, click the title to access available options
• Select Eudora and click Change for all...
• If you followed the previous steps a message should appear: This change will be applied to all files with P7M extension. Next, click the Continue button to finalize the process.

Step 4. Check the P7M for errors

You closely followed the steps listed in points 1-3, but the problem is still present? You should check whether the file is a proper P7M file. Problems with opening the file may arise due to various reasons.

1. The P7M may be infected with malware – make sure to scan it with an antivirus tool.

If the file is infected, the malware that resides in the P7M file hinders attempts to open it. It is advised to scan the system for viruses and malware as soon as possible or use an online antivirus scanner. If the scanner detected that the P7M file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Check whether the file is corrupted or damaged

If you obtained the problematic P7M file from a third party, ask them to supply you with another copy. During the copy process of the file errors may occurred rendering the file incomplete or corrupted. This could be the source of encountered problems with the file. It could happen the the download process of file with P7M extension was interrupted and the file data is defective. Download the file again from the same source.

3. Ensure that you have appropriate access rights

There is a possibility that the file in question can only be accessed by users with sufficient system privileges. Log out of your current account and log in to an account with sufficient access privileges. Then open the Digitally Encrypted Message file.

4. Check whether your system can handle Eudora

The operating systems may note enough free resources to run the application that support P7M files. Close all running programs and try opening the P7M file.

5. Check if you have the latest updates to the operating system and drivers

Regularly updated system, drivers, and programs keep your computer secure. This may also prevent problems with Digitally Encrypted Message files. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle P7M files.

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