mail.twc.com SMTP: RECEIVED: 421 Service not available, closing transmission channel

[FredFR]

telnet to mail.twc.com 587 from my home connection.

[EddieA]

Sorry, this is not really going to help, but I've been using that server all day without any issues, also from Los Angeles:

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to mail.twc.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
ehlo google.com
250-dnvrco-cmomta03 hello [23.243.xxx.170], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 30000000
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-STARTTLS
250 OK

Not really sure what might cause that, especailly both being telnet access, which would rule out any strange TCP packets being sent.

What device is connected to the modem, as I noticed that there is one internal IP before you hit the TWC gateway.

Cheers.

[LucidObscurity]

Very interesting. 

That hop you're seeing is an Asus RT-AC69. It's DMZ'd by the modem. Latest firmware. 

DNS is handled by a Server 2016 domain controller internally...turned off on the router, but resolution looks fine anyway.

I'm actually a bit of a way away from L.A. (near Temecula). Would you mind sending at least a partial tracert? I'm curious if at some point we take the same path and interested in the points we don't have in common...as it would seem they might be the culprits.

Thanks.

[EddieA]

Not the same route, but all (??) still inside TWC's network:

tracert mail.twc.com

Tracing route to dnvrco-twc-vip.email.rr.com [107.14.73.68]
over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms  Nethserver.BogoLinux.net [192.168.0.254]
  2     8 ms     8 ms    15 ms  142.254.237.37
  3    11 ms    12 ms     9 ms  agg61.igwdcaew01h.socal.rr.com [24.30.172.209]
  4    16 ms    22 ms    12 ms  agg30.lsaicaev01r.socal.rr.com [72.129.17.150]
  5    19 ms    12 ms    14 ms  agg26.lsancarc01r.socal.rr.com [72.129.17.0]
  6    16 ms    13 ms    14 ms  bu-ether26.lsancarc0yw-bcr00.tbone.rr.com [66.109.3.230]
  7    64 ms    70 ms    64 ms  bu-ether11.tustca4200w-bcr00.tbone.rr.com [66.109.6.5]
  8    65 ms    68 ms    62 ms  bu-ether16.dllstx976iw-bcr00.tbone.rr.com [66.109.6.1]
  9    60 ms    63 ms    63 ms  be7.ar3.pkv01.tbone.rr.com [66.109.10.97]
 10    62 ms    61 ms    60 ms  be3.ar1.pkv01.tbone.rr.com [66.109.10.103]
 11    60 ms    61 ms    60 ms  66.109.6.219
 12    61 ms    65 ms    60 ms  76.85.224.18
 13    60 ms    62 ms    60 ms  dnvrco-twc-vip.email.rr.com [107.14.73.68]

Trace complete.

Cheers.

[FredFR]

Called this in to support.  Tech walked through all the obvious options of the script.  Still being denied access to send/relay email to mail.twc.com.  telnet in and it doesn't even repond: long delay: then booted off.   This has been sent on to the engineers. 

As a side note, does it matter that my ID and PWD to access all the spectrum/rr/twc websites aren't sync'd?  Even after updating with all of them it still doesn't work.  Heck, clicking the sign in at the top of this page fails, but I can go to spectrum proper, log in, and then refresh this page and whoo, I'm logged in.

Something is not right for some users out there, not all or the screaming would be intolerable.

[lukesu]

I too am having this issue from my home IP, starting at the same time; None of my emails are getting out.

First instance was on 9/25/2018, 6:23pm CDT

I am in southeast Wisconsin.

IP at home resolves to a *.wi.res.rr.com domain name.

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to mail.twc.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
EHLO google.com
421 Service not available, closing transmission channel
Connection closed by foreign host.

From my work account, it does function:

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to mail.twc.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
EHLO google.com
250-dnvrco-cmomta03 hello [67.53.*.*], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 30000000
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-STARTTLS
250 OK

Work IP resolves to a *.west.biz.rr.com domain name.

[phila]

I am also having this issue, I was able to use port 25 for years without any issue until around yesterday afternoon. Now neither port 25 nor 587 are functioning at all. The error on the server happens as soon as you send any commands, so it is prior to any authentication or other potential client issues.

dig mail.twc.com

; <<>> DiG 9.9.5-3ubuntu0.18-Ubuntu <<>> mail.twc.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14186
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4000
;; QUESTION SECTION:
;mail.twc.com. IN A

;; ANSWER SECTION:
mail.twc.com. 176 IN CNAME dnvrco-twc-vip.email.rr.com.
dnvrco-twc-vip.email.rr.com. 166 IN A 107.14.73.68

;; Query time: 0 msec
;; SERVER: 192.168.235.10#53(192.168.235.10)
;; WHEN: Fri Oct 05 10:02:13 EDT 2018
;; MSG SIZE rcvd: 95

telnet mail.twc.com 25
Trying 107.14.73.68...
Connected to dnvrco-twc-vip.email.rr.com.
Escape character is '^]'.
554 dnvrco-cmomta03 cmsmtp ESMTP server not available AUP#O-1000

Connection closed by foreign host.

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to dnvrco-twc-vip.email.rr.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
EHLO xxx
421 Service not available, closing transmission channel
Connection closed by foreign host.

A working SMTP server:

telnet nwk-aaemail-lapp01.apple.com 25
Trying 17.151.62.66...
Connected to nwk-aaemail-lapp01.apple.com.
Escape character is '^]'.
220 nwk-aaemail-lapp01.apple.com ESMTP Fri, 5 Oct 2018 07:00:33 -0700
EHLO xxx
250-nwk-aaemail-lapp01.apple.com Hello cpe-71-72-***-***.cinci.res.rr.com [71.72.***.***], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250 STARTTLS
QUIT
221 2.0.0 nwk-aaemail-lapp01.apple.com Closing connection
Connection closed by foreign host.

[phila]

Also just tested from work and it works from our TWC business class service, but not from my residential service at home. There don't appear to be any routing issues either. It seems like the SMTP server may be rejecting my connection based on my IP address even though I am connecting from a TWC IP.

From work:

tracert mail.twc.com

Tracing route to dnvrco-twc-vip.email.rr.com [107.14.73.68]
over a maximum of 30 hops:

  1     1 ms     2 ms    <1 ms  10.10.10.1
  2     9 ms    10 ms     8 ms  142.254.144.165
  3    23 ms    19 ms    30 ms  network-024-029-006-225.cinci.rr.com [24.29.6.225]
  4    17 ms    14 ms    13 ms  be36.blasohdp01r.midwest.rr.com [65.29.38.68]
  5    16 ms    24 ms    20 ms  be28.clmkohpe01r.midwest.rr.com [65.29.1.44]
  6    33 ms    29 ms    29 ms  107.14.17.252
  7    48 ms    52 ms    47 ms  be5.ar3.pkv01.tbone.rr.com [66.109.10.99]
  8    66 ms    48 ms    50 ms  be3.ar0.pkv01.tbone.rr.com [66.109.10.93]
  9    48 ms    50 ms    47 ms  66.109.6.217
 10    51 ms    47 ms    48 ms  76.85.224.6
 11    50 ms    48 ms    47 ms  dnvrco-twc-vip.email.rr.com [107.14.73.68]

Trace complete.

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to dnvrco-twc-vip.email.rr.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
EHLO xxx
250-dnvrco-cmomta02 hello [174.98.***.***], pleased to meet you
250-HELP
250-AUTH LOGIN PLAIN
250-SIZE 30000000
250-ENHANCEDSTATUSCODES
250-8BITMIME
250-STARTTLS
250 OK
QUIT
221 2.0.0 dnvrco-cmomta02 cmsmtp closing connection
Connection closed by foreign host.

From home:

tracert mail.twc.com

Tracing route to dnvrco-twc-vip.email.rr.com [107.14.73.68]
over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms  router.whisky.local [192.168.235.254]
  2     7 ms    10 ms     8 ms  142.254.144.49
  3    27 ms    20 ms    13 ms  24.29.0.57
  4    13 ms    14 ms    14 ms  be38.blasohdp01r.midwest.rr.com [65.29.38.116]
  5    14 ms    15 ms    13 ms  be28.clmkohpe01r.midwest.rr.com [65.29.1.44]
  6    22 ms    23 ms    22 ms  107.14.17.252
  7    43 ms    44 ms    44 ms  be5.ar3.pkv01.tbone.rr.com [66.109.10.99]
  8    44 ms    44 ms    44 ms  be3.ar0.pkv01.tbone.rr.com [66.109.10.93]
  9    43 ms    43 ms    43 ms  66.109.6.217
 10    44 ms    46 ms    44 ms  76.85.224.10
 11    44 ms    44 ms    43 ms  dnvrco-twc-vip.email.rr.com [107.14.73.68]

Trace complete.

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to dnvrco-twc-vip.email.rr.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
EHLO xxx
421 Service not available, closing transmission channel
Connection closed by foreign host.

[lukesu]

@phila

That has been my observation and suspicion as well; that they're limiting or flagging residential IPs and permitting business class ones.  How is a customer expected to send ANY mail, using a thick client, if their connection is being dropped like this?

On the other hand, I haven't been able to successfully use port 25 without authentication in years. Or maybe I stopped trying after I got port 587 working with auth.

[jh0285]

Same problem here in Cincinnati, residential IP and I was relaying off of mail.twc.com for over a decade.  Sometime on September 22 that ceased:

telnet mail.twc.com 587
Trying 107.14.73.68...
Connected to mail.twc.com.
Escape character is '^]'.
220 Welcome to Road Runner. WARNING: *** FOR AUTHORIZED USE ONLY! ***
helo mail.domain.com
421 Service not available, closing transmission channel
Connection closed by foreign host.

 

A couple of days later, they let me relay again but then a couple days after that they turned it back off.

I am not blacklisted.

Please open up relay for residential IPs in the TWC network again!  I'm begging you.