This specific file often contains multiple layers of archives (e.g., a ZIP inside a RAR inside a 7z). You can use a recursive extraction command:
In many versions of this challenge, the "mail" refers to or raw email data hidden in the Slack space of the archive. mailmailmail.rar
Check for attachments or encoded strings in the email. Decoding these usually reveals the final flag or the next stage of the puzzle. This specific file often contains multiple layers of