> I repeat, you misunderstood the documentation. Postfix computes its best > guess at the FQDN when you DO NOT *explicitly* set myhostname, in main.cf.
The issue is NOT that I wanted Postfix to willy-nilly mangle $myhostname into a FQDN on my behalf. If there were a private keyword of $fqdn that was supported in the configuration, then yes, I would fully expect Postfix to intelligently determine if $fqdn should equal $myhostname or $myhostname.$mydomain modulo the presence of dots. The issue is narrowly concerning HELO only! It's the only important case where stuff can and does go badly if it's malformed. By perverting the very definition of what is a hostname, Postfix sets the user up for unexpected problems. If Postfix is going to deviate from accepted norms, then the least it could do is alert the admin that "Oh by the way since our defaults assume you subscribe to our redefining of the term 'hostname' to actually mean 'FQDN' (or be prepared for bad things), we see that your hostname isn't a FQDN, and you might want to change that or update 'smtp_helo_name' and some other settings (TBD) before you get blackballed and wonder what the hell just happened." (aside: I would also suggest $myorigin should likewise always default to $fqdn, and $mydestination have both short and fully-qualified hostnames as standard). Other pieces of software are cognizant enough to look for questionable values and to gripe accordingly. At the very least I was asking for a big ol' gripe, or logic on this one code-path that tries to do the right thing by default, or a 1-liner in the docs making it damn obvious that if $myhostname wasn't a FQDN you had better be running off-net or strongly urged to validate 'smtp_helo_name' and other potentially very important settings. If the Postfix philosophy is to assume admins by definition will have read the source code so they can accurately intuit every knock-on effect of one of their choices, then we might as well go back to nasty ol' Sendmail. Surprising users with non-intuitive behavior is not nice. To paper it over with "you changed a default, you should have knowed" is similarly unhelpful. > Postfix has been around for 22 years, and this has not been an issue for the > vast > majority of users. Who luckily never change defaults or just go along with Postfix' in-house redefining of the term 'hostname'. Not to mention RBL were few and far between if even present for much of that 22 years. Now everyone and their dog runs hosted email of one kind or another and the rules are massively more strict. SPF records are a new invention, and automated blacklisting instigated by massive bot farms is new as well. Anyhow, peace out. I forked the code and will update the logic as IMO it should have been all along.
