I would like to compress and archive thousands of E-Mails in .eml-Format every month. Most of the data is encoded in BASE64 within the .eml-files.
Is there a strong, stable archiver that can decode and encode BASE64 on the fly?
I would prefer strong, maybe asymmetric compression, like 7-zip with large dictionary and I need safe encryption. Compression can be very slow and decompression can be slow.
I tried precomp on each file to decode the BASE64. Generally it worked but I had some corruption with the closed-source-precomp-version. I have not tried newer open-source-versions yet.