I am using mysql (quite successfully in most cases) to do lookups for a variety of reasons in postfix.
Recently, I had some issues with a domain lookup and in the testing tried varying my MySQL query between using %d and %s as the lookup key. The documentation is clear on this when the query is for an address. It may be as clear, and I may not be understanding this, but I would like to ask for help understanding the difference when the lookup is for a domain. In this case, I have in main.cf: relay_domains = mysql:/etc/postfix/mysql_relay_domains.cf and the query in /etc/postfix/mysql_relay_domains.cf is: query = SELECT 'OK' FROM domain WHERE domain='%d' AND type='relay' I chose %d because I'm looking up only the domain in this case. I noticed that this worked fine when the domain in question is of the form "domain.tld" but didn't work (meaning the result returned from postmap -q... was null) when the domain is of the form "sub.domain.tld" (even though "sub.domain.tld" is in the "domain" table with type "relay"). When I changed the query to use %s, it worked in both cases. So my questions are: 1) Is this expected behavior? 2) in the case where the lookup is for a domain, what is the operative difference between using %d and %s I am hoping to gain a better understanding of these two substitutions. Recommendations on best-practices are appreciated as well, but I'd like to understand the expected behavior. If this is documented and I missed it or didn't understand it well, please point me to the documentation page.
