If a .7z file is too large for email or specific storage, 7-Zip can split it into smaller "chunks" (e.g., X1.7z.001 , X1.7z.002 ) which can then be rejoined. How to recover corrupted 7z archive
A 7z archive starts with a 32-byte header containing the file's signature and a link to the end header. Compression Levels (The "X" Parameter)
It can handle archives up to 16,000,000,000 GB.