I have definitely had this issue with Haraka (a highly scalable SMTP server). On the one hand we have Craigslist as a user, who have been incredibly open and contributed heavily to the project, and on the other we have had people post cryptic bug reports that it didn't work for them, but clearly they were trying to use it at an interesting scale, and we would love to have helped.<p>We pride ourselves on being one of the friendliest MTA communities out there, so to find people who give up and quit using it is always sad. Many times we've contributed custom code to companies for free to help them out, but we can't do that if you are silent. So speak up, companies, even if it's only in private messages.