Solution (almost certainly): postfix fails to launch at boot

[Bill Cole]

On 11 Jan 2020, at 13:32, Steven Smith wrote:

> • Edit /etc/postfix/master.cf as Gerben suggests.
>
> My concern about the second option is that it will never give the 
> macOS postfix a chance to do what it wants to do a boot time

That gives Apple too much credit, e.g. assumes that someone competent in 
Cupertino has thought about the contents of master.cf and consciously 
chosen to enable and disable the many available services and components 
of Postfix. It is entirely pointless to fire up network listeners for 
SMTP and initial mail submission on ports 25 and 587 with the overall 
config Apple provides, which is underlined by the fact that the sole 
master.cf override for submission cannot work without the specification 
of a X.509 certificate which does not exist.

The purpose of the macOS Postfix config is to service the local mail 
submission queue, which is expected to function by a universe of 
POSIX-compliant software. Unless you do something by hand to hook your 
MacPorts Postfix installation into the standard macOS local mail 
subsystem, you should leave that useful part of Apple's Postfix in 
place. There is no utility provided by its network listeners, so 
disabling them is safe.

> and I don’t know what the unintended consequences would be.

Thanks to the modular design of Postfix, disabling smtpd, postscreen, 
and submission does nothing but turn off those services. Nothing uses 
them (or even CAN use them, without modifying the default macOS config) 
so there are no secondary consequences.

> Also, every time you update the system this fix will get undone.

Well, maybe. Updates seem to create a weird mess of variant config files 
in /etc/postfix under normal circumstances and it is not clear to me 
from looking at the systems I have available what the behavior is 
regarding local changes. Installing and/or using Server.app (e.g. as an 
admin client for another machine really running Server) may have 
polluted my systems where I have evidence.

> Does macOS 10.14+ have an published approach to turn off native 
> postfix completely?

That should not matter, because 10.14+ (Mojave & Catalina) are entirely 
unfit for and hostile to server duties. The best answer to the question 
"How do I make Postfix work well on modern macOS?" is simply: "You 
don't."

But of course, the answer to *your* question is: NO. Maybe some have 
been "published" by people who haven't thought out the details 
carefully, but I wouldn't advise using one of those... Apple offers no 
useful support for macOS as a server platform aside from the shriveled 
remains of Server.

-- 
Bill Cole
bill at scconsult.com or billcole at apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Not For Hire (currently)