"HQ-Mail-Access" is common slang in hacker forums for "High Quality" mail access. This indicates the credentials (usually in email:password format) are claimed to be valid or verified for logging directly into email accounts.
Files like these are often distributed or sold on dark web forums and Telegram channels. 300-K HQ-Mail-Access .txt
Attackers use these lists to gain unauthorized access to personal or corporate email accounts. "HQ-Mail-Access" is common slang in hacker forums for