Service not available

Having trouble emailing a domain. When trying to email any address on
this domain, I get the following back in my gwia logs.

15:03:12 116C MSG 4263532 Analyzing result file:
/media/nss/DATA/campgwia/wpgate/gwia/result/r6659f65.322
15:03:12 116C MSG 4263532 Detected error on SMTP command
15:03:12 116C MSG 4263532 Command: RCPT TO:<email_address>
15:03:12 116C MSG 4263532 Response: 421 Service not available, closing
transmission channel

If I try telnetting to either of their mail servers on port 25 from my
gwia, I get this:

ccg-gwia:~ # telnet mailserver_IP 25
Trying mailserver_IP...
Connected to mailserver_IP.
Escape character is '^]'.
220 mailserver.domain.com ESMTP Mail Gateway

Of course they say it's on our end, and we *can* email other external
domains, just not this one.

Any suggestions?

--
Stevo

Tags:

  • Stevo,

    try a complete manual mail send via telnet, since your GWIA receives the error after the RCPT TO command. maybe this reveals something.

    Uwe


    --
    Novell Knowledge Partner
    Please don't send me support related e-mail unless I ask you to do so.
  • Am 07.12.2015 um 23:11 schrieb Stevo:
    > Having trouble emailing a domain. When trying to email any address on
    > this domain, I get the following back in my gwia logs.
    >
    > 15:03:12 116C MSG 4263532 Analyzing result file:
    > /media/nss/DATA/campgwia/wpgate/gwia/result/r6659f65.322
    > 15:03:12 116C MSG 4263532 Detected error on SMTP command
    > 15:03:12 116C MSG 4263532 Command: RCPT TO:<email_address>
    > 15:03:12 116C MSG 4263532 Response: 421 Service not available, closing
    > transmission channel
    >
    > If I try telnetting to either of their mail servers on port 25 from my
    > gwia, I get this:
    >
    > ccg-gwia:~ # telnet mailserver_IP 25
    > Trying mailserver_IP...
    > Connected to mailserver_IP.
    > Escape character is '^]'.
    > 220 mailserver.domain.com ESMTP Mail Gateway
    >
    > Of course they say it's on our end, and we *can* email other external
    > domains, just not this one.
    >
    > Any suggestions?
    >


    At any rate, *they* don't like something about "you", what exactly that
    is is usually their business to know and tell you, but we all know how
    this goes in this industry...

    Do you by chance have DSN (delivery status notification) enabled? There
    are recently some cases of external email systems that bark on that.
    Maybe try without it.

    CU,
    --
    Massimo Rosen
    Novell Knowledge Partner
    No emails please!
    http://www.cfc-it.de
  • Massimo Rosen sounds like they 'said':

    > Do you by chance have DSN (delivery status notification) enabled?
    > There are recently some cases of external email systems that bark on
    > that. Maybe try without it.
    >
    > CU,


    So my response to Massimo's comment is...

    That didn't seem to help. I did contact someone from their IT dept and
    forwarded him the undeliverable response I got back, guess I'll see
    what that reveals.

    --
    Stevo
  • Uwe Buckesfeld sounds like they 'said':

    > Stevo,
    >
    > try a complete manual mail send via telnet, since your GWIA receives
    > the error after the RCPT TO command. maybe this reveals something.
    >
    > Uwe


    So my response to Uwe's comment is...

    As far as I can tell, the email went through, never got a 421 error
    when telnetted into their email gateway. I did however get this error
    when I tried the helo or ehlo command:

    500 5.5.2 unrecognized command

    --
    Stevo
  • So, got a response from their IT:

    "It looks like your emails are getting rejected by our mail server
    because your HELO domain name (our spam filtering box (acts as outbound
    email relay also)) does not resolve to an IP address. Your emails will
    continue to be blocked until this is resolved due to our efforts to
    reduce incoming spam. Please forward this email to your IT department
    to get this resolved.

    Per industry standard RFC5321, the FQDN should be resolvable to an IP
    address."

    Changed a setting in this box to echo our MX record instead of the
    default, email flowing to this domain now.

    --
    Stevo
  • Make sure you have an A record for the name in the host name field in GWIA. Also, while it's technically only necessary that you have a PTR, some sites require that your PTR actually is the same as the helo string. In other words, mail.mydomain.com must have an A record. Also, while the PTR from my address 123.123.123.123 could be anything.anywhere.com, some mail servers are requiring that the PTR actually say mail.mydomain.com.
  • Am 09.12.2015 um 04:56 schrieb dzanre:
    > Also,
    > while the PTR from my address 123.123.123.123 could be
    > anything.anywhere.com, some mail servers are requiring that the PTR
    > actually say mail.mydomain.com.


    While that occasionally happens indeed, these sites/admins usually
    quickly learn they're nuts, as they won't receive mail from google,
    yahoo, microsoft....

    CU,
    --
    Massimo Rosen
    Novell Knowledge Partner
    No emails please!
    http://www.cfc-it.de
  • dzanre sounds like they 'said':

    >
    > Make sure you have an A record for the name in the host name field in
    > GWIA. Also, while it's technically only necessary that you have a
    > PTR, some sites require that your PTR actually is the same as the helo
    > string. In other words, mail.mydomain.com must have an A record.
    > Also, while the PTR from my address 123.123.123.123 could be
    > anything.anywhere.com, some mail servers are requiring that the PTR
    > actually say mail.mydomain.com.


    So my response to dzanre's comment is...

    We use Gwava and found the place to change the HELO from default to
    what our MX record is, that seemed to have fixed it.

    --
    Stevo