[sf-lug] Mail problems (or Firefox, or systemd,...)

[Michael Paoli]

> From: "Ken Shaffer" <kenshaffer80 at gmail.com>
> Subject: [sf-lug] Mail problems (or Firefox, or systemd,...)
> Date: Fri, 14 Dec 2018 17:24:39 -0800

> Anyone else having email problems?  Last month, systemd on my Ubuntu 18.04

Email problem(s)?  I'm sure some other person(s) on the planet are having
email problem(s).  Uhm, what kind of email problems?  That's not very
specific.

> stopped resolving mail.comcast.net.  No known changes on my part, not even

That sounds like a DNS problem, not an email problem.  What led you to
concluded it stopped resolving mail.comcast.net?  Did you use
delv(1), or dig(1), or nslookup(1), or ... what, what command exactly
did you run to conclude that, and exactly what output, including any
standard error output, did you get?  I find no difficulty resolving it, e.g.:
$ delv mail.comcast.net. CNAME +nottl
; fully validated
mail.comcast.net.       IN      CNAME   imap.ge.xfinity.com.
mail.comcast.net.       IN      RRSIG   CNAME 5 3 300 20181218174145  
20181211143645 26550 comcast.net.  
O4XeIAvfzWYjhBJFcTlIrF/mU6oTYOssV2TmHOYEnCOUmzIY/ziUbf0J  
rkwpuykdCybKx60AT2OugriGW+O3vpg8M+HQ81eW8prTcsPic5KCi4tv  
UGzbpUQz9glGQh9N1nJ/3DarONjo6VzSxG2nj3Jqzm2GsZp5Pt+8yYJp K/g=
$ delv imap.ge.xfinity.com. MX +nottl
;; resolution failed: ncache nxrrset
; negative response, unsigned answer
; imap.ge.xfinity.com.  IN      \-MX    ;-$NXRRSET
; ge.xfinity.com. SOA gtd03-d.northlake.il.ndcchgo.comcast.net.  
hostmaster.gslb03-d.northlake.il.ndcchgo.comcast.net. 8225 10800 3600  
604800 60
$ delv imap.ge.xfinity.com. A +nottl
; unsigned answer
imap.ge.xfinity.com.    IN      A       96.116.224.161
imap.ge.xfinity.com.    IN      A       96.116.224.173
imap.ge.xfinity.com.    IN      A       96.116.224.178
imap.ge.xfinity.com.    IN      A       96.116.224.179
imap.ge.xfinity.com.    IN      A       96.118.18.230
imap.ge.xfinity.com.    IN      A       96.118.18.240
imap.ge.xfinity.com.    IN      A       96.118.18.249
imap.ge.xfinity.com.    IN      A       96.118.18.255
imap.ge.xfinity.com.    IN      A       96.118.19.2
imap.ge.xfinity.com.    IN      A       96.118.19.3
imap.ge.xfinity.com.    IN      A       96.118.19.5
imap.ge.xfinity.com.    IN      A       96.118.19.7
imap.ge.xfinity.com.    IN      A       96.118.19.8
imap.ge.xfinity.com.    IN      A       96.118.19.10
imap.ge.xfinity.com.    IN      A       96.118.19.13
imap.ge.xfinity.com.    IN      A       96.118.19.14
$ delv imap.ge.xfinity.com. AAAA +nottl
; unsigned answer
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe02:e030
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe24:267a
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe2c:404
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe30:bdb7
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe4d:14e8
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe5f:cb4a
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe86:181a
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe8e:f723
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fe9d:38f3
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fea1:611f
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:febb:780e
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fec7:c9b7
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fed0:efaa
imap.ge.xfinity.com.    IN      AAAA    2001:558:fc18:2:f816:3eff:fefa:a7da
imap.ge.xfinity.com.    IN      AAAA    2001:558:fee2:1000:f816:3eff:fe11:9a89
imap.ge.xfinity.com.    IN      AAAA    2001:558:fee2:1000:f816:3eff:fea1:c548
$

> an update, it just stopped working, but none of the other sites I visit had
> a problem.  Seems some longstanding issues with DNS on systemd, oh well,

With only and exactly the one domain?  That sounds quite odd.
With systemd?  Really, how exactly did you isolate it to systemd having
issue with the domain in DNS, and nothing else having such DNS issues?

> not wanting to get too dirty under the hood (on an otherwise untouched
> system), I just took the suggestion to redirect /etc/resolv.conf to the

Suggestion?  What official documentation suggests that?
If not official documentation, what authoritative source "suggests" such?

> /run/systemd/resolve/resolv.conf file instead of the .../stub-resolv.conf.
> (pointing the nameserver to my router instead of 127.0.0.53). That  fixed

And why would you point your nameserver to your router?  A router doesn't
typically do DNS, ... unless maybe you're talking some "home router"
that does somethin' like router/NAT/SNAT/DHCP server/web browser/
{cable|DSL} "modem"/...

Hey, you can run a nameserver on whatever IP address(es) one has access to,
but 127.0.0.53?  Sounds like someone's playin' cutesie to do that.

> things, until my gmail through Firefox stopped working (on my 18.04, FF

gmail through Firefox?  Wait a minute, that's a browser.  Unless you've
got Firefox (or some other Mozilla bits) doing SMTP, POP, or IMAP or the
like, you're not talkin' email problem, you're talkin' somebody's web
thingy not doing quite what you want/expect, and your client isn't even
doing email, just a browser talkin' data to/from some webserver ... maybe
that's to some back-end email stuff, but sounds like that's not on your
host, and if there's email issue, that's elsewhere.  Is Google gmail web
server runnin' Ubuntu 18.04?  I kind'a doubt it.

What's an FF phone?  Is that as in 0xFF?  Or Firefox (but it's not FireFox),
or is that some Fortran compiler?  Firefox on a phone?  Naw, phones don't
run Firefox.  Maybe you mean some small portable computing device that
can also make and/or receive phone calls?  Or is your "phone" running
some Firefox or Mozilla based operating system? ... But I thought you
said Ubuntu?  But works on your FF phone?  Still don't know what you
mean by FF phone ... for all I know that could be Freaky Friday phone, ...
what day of the week did you have the problem?

> phone and FF 16.04, & Chrome were still OK).  Most unhelpful error message,

Chrome OK, but Firefox not?  That doesn't sound like an email or systemd
problem.  And do you really mean Chrome, or do you mean Chromium?  Which
is it that you're actually using?  On Linux?  This is a Linux user group
list, so would tend to presume Linux ... which would tend to imply
Chromium ... unless perhaps you're doing it on Chrome OS or Android - which
are flavors of / based upon Linux ... but you stated Ubuntu, which
neither Chrome OS nor Android are.

> "Sorry that didn't work try again".  Cleaned caches, history, etc.  No
> fix.  Finally found a suggestion to turn off the blocking of trackers (was
> only using the default baasic stuff anyway) -- That did it, Google insists

Sounds like a browser client issue.  Turn off blocking of trackers ... that
could be hazardous.  Found "a suggestion"?  Oh, again, what official
documentation, or, notwitstanding that, how 'bout authoritative source?

> now that my Firefox not block any trackers.  I'll look around to see if
> there's any granularity on this, but I just saw a few checkboxes.  Sigh.
> Ken

Sounds more like you're dealing with a web site that does things in an
improper and/or insecure way, and to "fix" your issue, you decided to go
along with doing things in an insecure way.  :-/

Yeah, I know, much 'o this has been more-or-less mentioned and commented
upon downthread, ... but I thought I'd reemphasize some points (and in
perhaps a slightly different manner).

You might want to also have a good look at:
http://www.catb.org/esr/faqs/smart-questions.html