Subject: Re: Null pointer dereference of cmd_name in shell.c
From: Ondřej Jirman
Date: Sun, 7 Jun 2020 17:40:00 +0200
On Sun, Jun 07, 2020 at 03:24:52PM +0000, lazuse wrote:
> On Sunday, June 7, 2020 3:11 PM, Ondřej Jirman <firstname.lastname@example.org> wrote:
> > On Sun, Jun 07, 2020 at 02:46:53PM +0000, lazuse wrote:
> > > On Monday, June 1, 2020 6:55 PM, Ondřej Jirman email@example.com wrote:
> > >
> > > > MX record is not necessary if the mail server is running on the same server
> > > > as pointed to by the A record.
> > >
> > > According to RFC 5321, 'the "implicit MX" rule above applies only
> > > if there are no MX records present. If MX records are present, but
> > > none of them are usable, this situation MUST be reported as an error.'
> > > In the case of megous.com, there exists an MX record vps.xff.cz.
> > > I am unsure how ProtonMail handled this situation, but my local
> > > OpenSMTPD reported it as an error and failed to deliver mails.
> > It really looks fine to me, and the whole setup is almost
> > the simplest possible:
> > - my address is firstname.lastname@example.org
> > - megous.com MX is vps.xff.cz
> > - vps.xff.cz A points to the address of the mail server
> > mxtoolbox score is pretty much perfect:
> > https://mxtoolbox.com/domain/megous.com/?source=findmonitors
> > Not sure what your OpenSMTPD complained about exactly.
> I figured it was because I used Quad9 DNS on my server,
> which I am aware is not the best practice, but it is blocking
> your vps.xff.cz domain because of "ThreatConnect":
> That is the reason I was under the impression that vps.xff.cz
> was a NXDOMAIN and that my mail failed to deliver.
> Sorry about that.
Interesting. I've found no way to report false blocking on ThreatConnect's
website. What jokers.
> > thank you and regards,
> > o.