On Thu, Apr 14, 2022 at 01:22:03AM -0400, Viktor Dukhovni <postfix-us...@dukhovni.org> wrote:
> On Thu, Apr 14, 2022 at 12:25:11AM -0400, Greg Klanderman wrote: > > > > This is naturally documented in access(5), and also in postconf(5) > > > under: > > > > > > smtpd_null_access_lookup_key (default: <>) > > > The lookup key to be used in SMTP access(5) tables instead of the > > > null sender address. > > > > Thank you Viktor, I had searched access(5) for 'blank' and 'empty' but > > not 'null'. > > Sadly nobody *reads* documentation these days, all we seem to know how > to do is *search*. The access(5) document is logically organised, and > the text in question is logically located under: > > EMAIL ADDRESS PATTERNS > > With lookups from indexed files such as DB or DBM, or from networked > tables such as NIS, LDAP or SQL, patterns are tried in the order as > listed below: > > user@domain > Matches the specified mail address. > > domain.tld > Matches domain.tld as the domain part of an email address. > > The pattern domain.tld also matches subdomains, but only when > the string smtpd_access_maps is listed in the Postfix par- > ent_domain_matches_subdomains configuration setting. > > .domain.tld > Matches subdomains of domain.tld, but only when the string > smtpd_access_maps is not listed in the Postfix par- > ent_domain_matches_subdomains configuration setting. > > user@ Matches all mail addresses with the specified user part. > > Note: lookup of the null sender address is not possible with some types > of lookup table. By default, Postfix uses <> as the lookup key for such > addresses. The value is specified with the smtpd_null_access_lookup_key > parameter in the Postfix main.cf file. > > In other words, looking at the topics covered and then reading the text > under the most relevant topic, rather than searching for a specific > keyword, would have quickly found the answer. Sadly, we're losing the > skill to read more than a snippet found via keyword search. :-( > > -- > Viktor. Yeah, an important part of writing documentation these days is to address the fact that any paragraph might be the first paragraph. A reader might turn up at any point in any document, and it's great if they can find everything they need right there (or pointers to the rest). But it is hard to make that possible. It probably takes as much effort as it takes to write the software being documented. That's often the easy bit. :-) So, the advice for readers of documentation is to actually read the documentation. You won't regret it. :-) cheers, raf
