Like its author, Nmap isn't perfect. But you can help make it better by sending bug reports or even writing patches. If Nmap doesn't behave the way you expect, first upgrade to the latest version available from https://nmap.org. If the problem persists, do some research to determine whether it has already been discovered and addressed. Try searching for the problem or error message on Google since that aggregates so many forums. If nothing comes of this, create an Issue on our tracker (http://issues.nmap.org) and/or mail a bug report to <[email protected]>. If you subscribe to the nmap-dev list before posting, your message will bypass moderation and get through more quickly. Subscribe at https://nmap.org/mailman/listinfo/dev. Please include everything you have learned about the problem, as well as what version of Nmap you are using and what operating system version it is running on. Other suggestions for improving Nmap may be sent to the Nmap dev mailing list as well.

If you are able to write a patch improving Nmap or fixing a bug, that is even better! Instructions for submitting patches or git pull requests are available from https://github.com/nmap/nmap/blob/master/CONTRIBUTING.md

Particularly sensitive issues such as a security reports may be sent directly to Nmap's author Fyodor directly at <[email protected]>. All other reports and comments should use the dev list or issue tracker instead because more people read, follow, and respond to those.