.P7Z File

The p7z file extension is used for e-mail messages, that use S/MIME (Secure/Multipurpose Internet Mail Extensions) encryption with compression.

S/MIME (Secure / Multipurpose Internet Mail Extensions) is a standard for public key encryption and signing of e-mail encapsulated in MIME.

To read S/MIME encrypted files, you have to install the PKCS (Public-Key Cryptography Standards) certificate to your e-mail client.

MIME types:
application/pkcs7-mime

How to open:

E-mail clients should be able to handle this particular file type and read the messages.

How to convert:

There is probably no way how to simply convert these files. However, once you get the email image, you could copy and paste the content to a standard text/document format.