> Postfix tries ALL CONFIGURED ADDRESS TYPES, Your capitalization of "configured address types" seems to imply this is a well-defined term in the context of Postfix configuration, but sorry, I don't know how it's defined.
> and when NO CONFIGURED ADDRESS TYPE works This seems to imply Postfix tried an A lookup for "smtp" before and that failed. However, a simple "host smtp" works as expected, so the problem must be a bit less obviuos. > it logs the LAST ERROR. OK, thanks for that explanation. What's the suggested method for finding out what's wrong with my setup so that the A lookup failed?
