Before reporting bugs/problems with released OpenSMTPD versions, go through this checklist:
If nothing looks like it addresses your problem, then use the bug tracker to submit a bug report (but see below for reporting security bugs privately).
You can reach the OpenSMTPD developers by sending email to one of the following lists.
Try to pin-point the exact problem. Never give vague instructions, or detail vague problems like "it crashes." Talk to others on IRC or use some other forum such as the mailing list archives to confirm that it is new, repeatable, etc., and make sure it is not a local problem.
For an excellent overview of the art of reporting bugs, see Simon Tatham's How to Report Bugs Effectively. Remember, the better the information in your report, the better the chance that your problem will be resolved.
New features are accepted, especially with code that implements your suggested new feature. If someone else writes code for your new feature, the chances are that it will be misunderstood and created so that you will not recognize it.
Types of bug reports in order of desirability: