. However, it is important to note that many tools in this category are distributed via unverified third-party sites and may be classified as "grayware" or tools used for unauthorized activities like spamming or brute-forcing email accounts. What is an SMTP Scanner? Simple Mail Transfer Protocol (SMTP)
If the server returns 250 OK or similar for RCPT TO to a domain that is not its own, the server is an open relay.
When using such tools, always ensure you have the necessary permissions and are complying with all relevant laws and regulations.
: The ability to open multiple simultaneous connections (sometimes up to 40) to speed up the scanning of large IP ranges.
: A parallelised login cracker that supports SMTP and is widely used by security professionals for penetration testing.
