The Apache SSHD developers communicates using our Mailing Lists. If you have any questions, feedback or suggestions, you’re very welcome to join the list and send an email. We are also happy to receive bug reports and feature requests in our issue tracker.
The best chance of getting your bug or feature fixed is to provide a patch, if they fit our goals we will usually have them committed within a few days. The Apache Contributors page has excellent information on how to produce patches.
The git repository is also mirrored at GitHub. We do accept pull requests!