[sf-lug] (forw) Re: GMail users: check archives for Tue/Wed posts

[Rick Moen]

----- Forwarded message from Rick Moen <rick at linuxmafia.com> -----

Date: Thu, 25 Feb 2021 16:43:30 -0800
From: Rick Moen <rick at linuxmafia.com>
To: [a subscriber]
Subject: Re: [sf-lug] GMail users: check archives for Tue/Wed posts
Organization: If you lived here, you'd be $HOME already.

Quoting [subscriber]:

> On Wednesday, February 24, 2021 8:21 PM, Rick Moen
> <rick at linuxmafia.com> wrote:
>
> >> Wednesday afternoon and about 2pm today (Thursday).
>
> >> I noticed the problem about 1:30 pm today, and it took me a few
> >> minutes

> If I'm not a lot further gone than I realize, I believe you mean 2am
> rather than 2pm (in 2 places,) n'est pas?  Today is Thursday, isn't
> it? ... and it's still morning (certainly feels like it!)

You're right.  Sorry about the wrong day reference.  (I've amended the 
Subject header, above.)  It was a long and somewhat trying day.

At the time I _wrote_ that, it was indeed Wednesday (Mar. 24).  Around
2pm Wednesday, I had just worked out and scotched the technical issue
that had been the root cause of Gmail refusing all outbound mail from
linuxmafia.com (including SF-LUG mailing list mail) for the preceding
approximately 24 hours since some time around mid-day Tuesday Mar. 23.  

Rolling back...

On Tuesday, Mar. 23, a visiting guest accidentally cut AC power to my
server (by overloading the circuit breaker).  Although I immediately
intervened to bring my server back online and dissuade my guest from
again overloading the most important circuit breaker in my house, what I
did _not_ know is that my server came up with an autoconfigured IPv6 
address (what I had specifically and deliberately omitted from the
server configuration).  Gmail refuses to deliver to any SMTP host that
is detected to have an IPv6 address but lacks a reverse DNS entry for
that IPv6 address.

It took me a few minutes to figure out the nature of the problem, being
taken by surprise by Gmail's claim of my server having IPv6 -- the thing
I had carefully omitted from its configuration -- and remedy the
immediate problem by shutting down IPv6, pending a less-brutal fix in
the future.

----- End forwarded message -----