Asking smart questions

Your mail is being blocked or deferred and you’d like to know why.
Before you ask someone “why?” you should have done these things:

1. Read the rejection message
2. If the rejection message contains a URL, read the page it points to
3. Saved a full copy of the message that was sent

And you should have some pieces of information ready. If you’re asking via email, put this information in your initial email:

1. The recipients email address
2. The IP address of the sending machine
3. The exact rejection message you got
4. Whether this is a one-off instance, or whether you’re seeing a little / some / complete blocking at this domain / other related domains / many domains
5. Something that makes clear to the people reading your question that you’ve read the rejection message, and the web page it points to

And, if you think it might possibly be related to content-based blocking, then the content of the email – especially any URLs in it – might well be important. You should at least offer to provide the email, and ideally provide a copy with the initial question. Including a copy in the mail you send is fine, but making it available via a paste site works for email, and IM and IRC too.
While you’ll sometimes get useful answers to a question as vague as “Is anyone else seeing deferrals at Yahoo?”[1], you’re likely to get more useful answers in a timelier fashion (and annoy your peers less) if you ask your question in a smarter way.
How To Ask Questions The Smart Way is aimed at asking for technical support from hackers, but many of the suggestions are just as relevant for asking operational questions of your peers, or busy postmasters, or skeptical blacklist operators.
[1] Spoiler: Yes, they are.