for G Suite / Office 365
For ZIP Encryption feature, why does the filename sometimes shows up as [Auto_Compressed.zip] on the recipient side?
In the case that the filename exceeds 255 bytes after being encoded, the filename will be compressed and automatically turned into [Auto_Compressed.zip].
**Note that similar to email body message, attachment filename will also be encoded. The specification may differ depending on the encoding system. For Japanese, the rough estimate is around up to 60-70 characters allowed before the filename will be auto-compressed.