Office 365 SMTP Cracker

Features:

• Multi Server Auto Rotation : Cycles through all known Microsoft Office 365 SMTP endpoints including smtp.office365.com and smtp mail.outlook.com across multiple ports, ensuring no single server block kills your run.
• Server Health Tracking : Monitors failure rates per server in real time, automatically deprioritizing struggling endpoints so your threads always target the healthiest available servers.
• Exponential Backoff Engine : When a server starts failing, it gets progressively longer timeouts before retry starting at seconds and capping at 30 preventing wasteful hammering against already stressed infrastructure.
• Smart Retry Logic : Temporary blocks and rate limits trigger automatic retries with randomized delays, giving Microsoft's throttling systems time to cool down before attempting again.
• Direct SMTP Authentication : No API calls, no web scrapes, no guessing. Performs Direct SMTP AUTH LOGIN handshakes against live Microsoft servers to determine definitive VALID or INVALID status.
• Full Send Verification : Optional module that completes an entire SMTP transaction confirming the account can actually push mail to external inboxes, not just authenticate.
• Triple Account Classification : Every valid account gets tagged as LOGIN_ONLY, SEND_WORKING, or SEND_FAILED so you know exactly which ones are fully operational versus partially restricted.
• Granular Error Breakdown : Distinguishes between 8+ distinct failure types: bad credentials, no SMTP service, temporary blocks, rate limiting, connection refused, socket timeout, STARTTLS failure, and generic protocol errors.
• Rate Limit Detection : Catches Microsoft's throttling responses specifically, separating rate limited accounts from permanently blocked ones so you know which can be retried later.
• Temporary Block Recognition : Identifies transient lockouts versus permanent bans different error messages parsed to different buckets for accurate accounting.
• START TLS Auto Negotiation : Initiates encrypted SMTP sessions automatically on plaintext connections, matching real email client behavior and avoiding security triggered rejections.
• Configurable Thread Pool : Set anywhere from 1 to 100 concurrent workers scale from careful testing to full speed production runs depending on your proxy setup and risk tolerance.
• Queue Based Task Distribution : All combos feed into a thread safe queue workers pull dynamically as they finish. No static chunking, no idle threads, no wasted capacity.
• Real Time Hit Streaming : Valid credentials appear the instant they're found no waiting for batch completion, no refreshing required, just immediate visibility into your hits.
• Dual Output Logging : Automatically writes working accounts to one file and send failed accounts to another, both with full credentials and server details for immediate operational use.
• Timestamped Run Headers : Every session stamps date and time into both output files, making it trivial to track multiple runs and sort results by campaign.
• Latency Benchmarking : Measures authentication handshake time in milliseconds per account identify which servers are fastest and which accounts respond slowest.
• Connection Timeout Enforcement : Hard 10 second socket timeout on auth attempts, 15 second on send tests no hung threads stalling your entire operation.
• SMTP Level Exception Handling : Catches SMTPAuthenticationError, SMTPRecipientsRefused, SMTPSenderRefused, SMTPDataError, and generic SMTPException separately, routing each to the correct status bucket.
• MIME Compliant Test Messages : Send tests construct properly formatted multipart messages with From, To, Subject, and text body appearing as legitimate mail, not flagged as spam test patterns.
• Bulk File Ingestion : Handles any size combolist 1,000 lines or 1million with UTF 8 encoding and error tolerance for special characters in passwords.
• Custom Send Test Targeting : Configure any recipient address for send verification test against Gmail, Yahoo, custom domains, or a mix for true deliverability confirmation.
• Thread Safe Shared State : All server failure counters, backoff timers, and result queues protected by mutex locks no race conditions when 100 threads hit the same server.
• Randomized Retry Jitter : Adds sub second random delays to every backoff cycle, preventing synchronized retry waves that Microsoft's anti abuse systems detect and block.
• Zero External Dependencies : No third party APIs, no external validation services, no cloud calls. Every check runs direct socket to socket against Microsoft's infrastructure.
• Append Only Persistent Logs : Output files append rather than overwrite run the tool 50 times and keep all historical results intact without accidental data loss.