Convert OLM to P7Z

Understanding OLM and P7Z file formats

OLM files are archive files used by Microsoft Outlook for Mac to store emails, contacts, calendars, and other mailbox data. These files are specific to the Mac version of Outlook and are not natively compatible with Windows Outlook or other email clients.

P7Z files, on the other hand, are less common and are typically associated with encrypted or signed data, often using the PKCS #7 standard. However, the standard extension for PKCS #7 files is .p7m or .p7s, and .p7z is not widely recognized. Sometimes, users may confuse .p7z with .7z (7-Zip archives), but they serve different purposes.

Is direct OLM to P7Z conversion possible?

There is no direct or standard method to convert an OLM file to a P7Z file, as they serve entirely different purposes. OLM is for email data archiving, while P7Z is related to encrypted or signed data. If you need to extract emails from OLM and then encrypt or sign them, you would need to perform a two-step process: first, extract the data from OLM, then use encryption software to create a PKCS #7 archive (usually resulting in a .p7m or .p7s file).

How to extract data from OLM files

To extract emails and other data from an OLM file, you can use specialized software such as:

• Stellar Converter for OLM – Converts OLM files to PST, EML, or MBOX formats.
• OLM Extractor Pro – Exports OLM data to various formats including EML and MBOX.

After extraction, you can save the emails or files you wish to encrypt.

How to create a PKCS #7 (P7Z) file

Once you have the files you want to encrypt or sign, use a tool like OpenSSL to create a PKCS #7 archive. The typical output will be a .p7m or .p7s file, not .p7z. If you specifically need a .p7z extension, you can rename the file, but ensure the recipient understands the format.

Example command with OpenSSL:

openssl smime -sign -in message.eml -out message.p7m -signer mycert.pem

Recommended software for the process

• Stellar Converter for OLM – For extracting data from OLM files.
• OpenSSL – For creating PKCS #7 signed or encrypted files.

There is no single tool that converts OLM directly to P7Z, so a two-step process is required.

Summary

Direct conversion from OLM to P7Z is not supported due to the different purposes of these formats. Extract your data from OLM using a dedicated converter, then use encryption software like OpenSSL to create a PKCS #7 archive if needed.