I have to input HELO/EHLO commands twice before it registers on receiving server while testing SMTPIIS SMTP: 550 5.7.1 Unable to relayReverse DNS does not match SMTP BannerMail server on port 25 only response with 500 command not recognizedExchange emails not delivering for one userEnabling Basic Authentication on Exchange 2010 SP1Exchange 2007 issue internet receive connectorExchange 2003 SMTP does not receive RCPT from senderPostfix sender address rejected / using multiple addressesExim: Force email auth for users of local domainsSMTP-SASL authentification doesn't work

At what point in time did Dumbledore ask Snape to kill him?

How do I write "Show, Don't Tell" as a person with Asperger Syndrome?

My coworkers think I had a long honeymoon. Actually I was diagnosed with cancer. How do I talk about it?

How would a aircraft visually signal in distress?

PhD - Well known professor or well known school?

Did the first version of Linux developed by Linus Torvalds have a GUI?

Should an arbiter claim draw at a K+R vs K+R endgame?

Illustrator CC 2019 No canvas in new file

Turing patterns

Argon vs nitrogen for preserving wine

Are "living" organ banks practical?

How to build suspense or so to establish and justify xenophobia of characters in the eyes of the reader?

Are there downsides to using std::string as a buffer?

Indirectly defined macros: Undefined macro with "@" does not trigger compile error

How do you show, through your narration, a hard and uncaring world?

Show mappings for all function keys

How does an ordinary object become radioactive?

Example of non-trivial functors

Can anyone identify this tank?

Why only the fundamental frequency component is said to give useful power?

PTFE detoriation temperature

What are the peak hours for public transportation in Paris?

Why does Kathryn feel that she's already met Cole in 1990?

How to project 3d image in the planes xy, xz, yz?



I have to input HELO/EHLO commands twice before it registers on receiving server while testing SMTP


IIS SMTP: 550 5.7.1 Unable to relayReverse DNS does not match SMTP BannerMail server on port 25 only response with 500 command not recognizedExchange emails not delivering for one userEnabling Basic Authentication on Exchange 2010 SP1Exchange 2007 issue internet receive connectorExchange 2003 SMTP does not receive RCPT from senderPostfix sender address rejected / using multiple addressesExim: Force email auth for users of local domainsSMTP-SASL authentification doesn't work






.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty height:90px;width:728px;box-sizing:border-box;








1















We have an Exchange Server (2010) on site that sends our mail to the world using MX(DNS) records.
When I look at the queue, several domains have 421 4.4.2 Connection dropped due to ConnectionReset.
I've telnet into the SMTP port of the servers refusing connection and doing HELO or EHLO (domain) always returns Syntax error the first time it is submitted.
The second time the receiving server replies to the command.
Once I get the HELO or EHLO command to be received it takes all other commands as normal.



 220 smtp-gateway2.carleton.ca ESMTP Service ready
EHLO **********.ca
500 Syntax error, command unrecognized
EHLO **********.ca
250-Requested mail action okay, completed
250-8BITMIME
250-SIZE 20480000
250-ETRN
250-STARTTLS
250 OK


No backspaces or any other keystrokes besides what you see. I'm using our domain name that would be sending the email in the sample above.



Could this be the reason I am seeing the 4.4.2 error in our send queue? If so what would be causing this issue?



To telnet I'm using putty from our Exchange Server.



Extra information:
Web traffic for our company uses a different public IP than our Exchange server uses for mail/smtp. All information from Exchange that uses port 25 is forcefully being re-written to the correct public IP by the Firewall. There was an issue with mail having the incorrect public IP and being rejected because there is no rDNS for the web traffic IP.










share|improve this question






















  • I tried it a couple of times against that server and I could not reproduce that issue. I never got a syntax error and it responded properly the first EHLO. But, I was connected to that actual server, and you are not. Your connection seems to have been intercepted and diverted somewhere else.

    – Michael Hampton
    Nov 16 '16 at 20:53












  • Not sure what you mean by my connection was intercepted.

    – J.Houston
    Nov 16 '16 at 20:55












  • I mean I'm talking to smtp-gateway2.carleton.ca and it gives me completely different banners and responses. I think you're actually talking to some other server.

    – Michael Hampton
    Nov 16 '16 at 20:57











  • When I run a telnet session from my computer (which then uses the other public IP I get the following): 220 smtp-gateway2.carleton.ca ESMTP Sendmail 8.15.2/8.15.2; Wed, 16 Nov 2016 15:56:26 -0500 EHLO **********.ca 500 5.5.1 Command unrecognized: {EHLO **********.ca" EHLO **********.ca 250-smtp-gateway2.carleton.ca Hello [XXX.XXX.XX.42], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-EXPN 250-VERB 250-8BITMIME 250-SIZE 36700160 250-ETRN 250-STARTTLS 250-DELIVERBY 250 HELP

    – J.Houston
    Nov 16 '16 at 20:59












  • OK, that's the correct server. So now we can be sure that the problem is on your local computer or network. You can see that some additional characters were sent before your first EHLO.

    – Michael Hampton
    Nov 16 '16 at 21:08

















1















We have an Exchange Server (2010) on site that sends our mail to the world using MX(DNS) records.
When I look at the queue, several domains have 421 4.4.2 Connection dropped due to ConnectionReset.
I've telnet into the SMTP port of the servers refusing connection and doing HELO or EHLO (domain) always returns Syntax error the first time it is submitted.
The second time the receiving server replies to the command.
Once I get the HELO or EHLO command to be received it takes all other commands as normal.



 220 smtp-gateway2.carleton.ca ESMTP Service ready
EHLO **********.ca
500 Syntax error, command unrecognized
EHLO **********.ca
250-Requested mail action okay, completed
250-8BITMIME
250-SIZE 20480000
250-ETRN
250-STARTTLS
250 OK


No backspaces or any other keystrokes besides what you see. I'm using our domain name that would be sending the email in the sample above.



Could this be the reason I am seeing the 4.4.2 error in our send queue? If so what would be causing this issue?



To telnet I'm using putty from our Exchange Server.



Extra information:
Web traffic for our company uses a different public IP than our Exchange server uses for mail/smtp. All information from Exchange that uses port 25 is forcefully being re-written to the correct public IP by the Firewall. There was an issue with mail having the incorrect public IP and being rejected because there is no rDNS for the web traffic IP.










share|improve this question






















  • I tried it a couple of times against that server and I could not reproduce that issue. I never got a syntax error and it responded properly the first EHLO. But, I was connected to that actual server, and you are not. Your connection seems to have been intercepted and diverted somewhere else.

    – Michael Hampton
    Nov 16 '16 at 20:53












  • Not sure what you mean by my connection was intercepted.

    – J.Houston
    Nov 16 '16 at 20:55












  • I mean I'm talking to smtp-gateway2.carleton.ca and it gives me completely different banners and responses. I think you're actually talking to some other server.

    – Michael Hampton
    Nov 16 '16 at 20:57











  • When I run a telnet session from my computer (which then uses the other public IP I get the following): 220 smtp-gateway2.carleton.ca ESMTP Sendmail 8.15.2/8.15.2; Wed, 16 Nov 2016 15:56:26 -0500 EHLO **********.ca 500 5.5.1 Command unrecognized: {EHLO **********.ca" EHLO **********.ca 250-smtp-gateway2.carleton.ca Hello [XXX.XXX.XX.42], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-EXPN 250-VERB 250-8BITMIME 250-SIZE 36700160 250-ETRN 250-STARTTLS 250-DELIVERBY 250 HELP

    – J.Houston
    Nov 16 '16 at 20:59












  • OK, that's the correct server. So now we can be sure that the problem is on your local computer or network. You can see that some additional characters were sent before your first EHLO.

    – Michael Hampton
    Nov 16 '16 at 21:08













1












1








1








We have an Exchange Server (2010) on site that sends our mail to the world using MX(DNS) records.
When I look at the queue, several domains have 421 4.4.2 Connection dropped due to ConnectionReset.
I've telnet into the SMTP port of the servers refusing connection and doing HELO or EHLO (domain) always returns Syntax error the first time it is submitted.
The second time the receiving server replies to the command.
Once I get the HELO or EHLO command to be received it takes all other commands as normal.



 220 smtp-gateway2.carleton.ca ESMTP Service ready
EHLO **********.ca
500 Syntax error, command unrecognized
EHLO **********.ca
250-Requested mail action okay, completed
250-8BITMIME
250-SIZE 20480000
250-ETRN
250-STARTTLS
250 OK


No backspaces or any other keystrokes besides what you see. I'm using our domain name that would be sending the email in the sample above.



Could this be the reason I am seeing the 4.4.2 error in our send queue? If so what would be causing this issue?



To telnet I'm using putty from our Exchange Server.



Extra information:
Web traffic for our company uses a different public IP than our Exchange server uses for mail/smtp. All information from Exchange that uses port 25 is forcefully being re-written to the correct public IP by the Firewall. There was an issue with mail having the incorrect public IP and being rejected because there is no rDNS for the web traffic IP.










share|improve this question














We have an Exchange Server (2010) on site that sends our mail to the world using MX(DNS) records.
When I look at the queue, several domains have 421 4.4.2 Connection dropped due to ConnectionReset.
I've telnet into the SMTP port of the servers refusing connection and doing HELO or EHLO (domain) always returns Syntax error the first time it is submitted.
The second time the receiving server replies to the command.
Once I get the HELO or EHLO command to be received it takes all other commands as normal.



 220 smtp-gateway2.carleton.ca ESMTP Service ready
EHLO **********.ca
500 Syntax error, command unrecognized
EHLO **********.ca
250-Requested mail action okay, completed
250-8BITMIME
250-SIZE 20480000
250-ETRN
250-STARTTLS
250 OK


No backspaces or any other keystrokes besides what you see. I'm using our domain name that would be sending the email in the sample above.



Could this be the reason I am seeing the 4.4.2 error in our send queue? If so what would be causing this issue?



To telnet I'm using putty from our Exchange Server.



Extra information:
Web traffic for our company uses a different public IP than our Exchange server uses for mail/smtp. All information from Exchange that uses port 25 is forcefully being re-written to the correct public IP by the Firewall. There was an issue with mail having the incorrect public IP and being rejected because there is no rDNS for the web traffic IP.







smtp exchange-2010






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 16 '16 at 20:50









J.HoustonJ.Houston

62




62












  • I tried it a couple of times against that server and I could not reproduce that issue. I never got a syntax error and it responded properly the first EHLO. But, I was connected to that actual server, and you are not. Your connection seems to have been intercepted and diverted somewhere else.

    – Michael Hampton
    Nov 16 '16 at 20:53












  • Not sure what you mean by my connection was intercepted.

    – J.Houston
    Nov 16 '16 at 20:55












  • I mean I'm talking to smtp-gateway2.carleton.ca and it gives me completely different banners and responses. I think you're actually talking to some other server.

    – Michael Hampton
    Nov 16 '16 at 20:57











  • When I run a telnet session from my computer (which then uses the other public IP I get the following): 220 smtp-gateway2.carleton.ca ESMTP Sendmail 8.15.2/8.15.2; Wed, 16 Nov 2016 15:56:26 -0500 EHLO **********.ca 500 5.5.1 Command unrecognized: {EHLO **********.ca" EHLO **********.ca 250-smtp-gateway2.carleton.ca Hello [XXX.XXX.XX.42], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-EXPN 250-VERB 250-8BITMIME 250-SIZE 36700160 250-ETRN 250-STARTTLS 250-DELIVERBY 250 HELP

    – J.Houston
    Nov 16 '16 at 20:59












  • OK, that's the correct server. So now we can be sure that the problem is on your local computer or network. You can see that some additional characters were sent before your first EHLO.

    – Michael Hampton
    Nov 16 '16 at 21:08

















  • I tried it a couple of times against that server and I could not reproduce that issue. I never got a syntax error and it responded properly the first EHLO. But, I was connected to that actual server, and you are not. Your connection seems to have been intercepted and diverted somewhere else.

    – Michael Hampton
    Nov 16 '16 at 20:53












  • Not sure what you mean by my connection was intercepted.

    – J.Houston
    Nov 16 '16 at 20:55












  • I mean I'm talking to smtp-gateway2.carleton.ca and it gives me completely different banners and responses. I think you're actually talking to some other server.

    – Michael Hampton
    Nov 16 '16 at 20:57











  • When I run a telnet session from my computer (which then uses the other public IP I get the following): 220 smtp-gateway2.carleton.ca ESMTP Sendmail 8.15.2/8.15.2; Wed, 16 Nov 2016 15:56:26 -0500 EHLO **********.ca 500 5.5.1 Command unrecognized: {EHLO **********.ca" EHLO **********.ca 250-smtp-gateway2.carleton.ca Hello [XXX.XXX.XX.42], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-EXPN 250-VERB 250-8BITMIME 250-SIZE 36700160 250-ETRN 250-STARTTLS 250-DELIVERBY 250 HELP

    – J.Houston
    Nov 16 '16 at 20:59












  • OK, that's the correct server. So now we can be sure that the problem is on your local computer or network. You can see that some additional characters were sent before your first EHLO.

    – Michael Hampton
    Nov 16 '16 at 21:08
















I tried it a couple of times against that server and I could not reproduce that issue. I never got a syntax error and it responded properly the first EHLO. But, I was connected to that actual server, and you are not. Your connection seems to have been intercepted and diverted somewhere else.

– Michael Hampton
Nov 16 '16 at 20:53






I tried it a couple of times against that server and I could not reproduce that issue. I never got a syntax error and it responded properly the first EHLO. But, I was connected to that actual server, and you are not. Your connection seems to have been intercepted and diverted somewhere else.

– Michael Hampton
Nov 16 '16 at 20:53














Not sure what you mean by my connection was intercepted.

– J.Houston
Nov 16 '16 at 20:55






Not sure what you mean by my connection was intercepted.

– J.Houston
Nov 16 '16 at 20:55














I mean I'm talking to smtp-gateway2.carleton.ca and it gives me completely different banners and responses. I think you're actually talking to some other server.

– Michael Hampton
Nov 16 '16 at 20:57





I mean I'm talking to smtp-gateway2.carleton.ca and it gives me completely different banners and responses. I think you're actually talking to some other server.

– Michael Hampton
Nov 16 '16 at 20:57













When I run a telnet session from my computer (which then uses the other public IP I get the following): 220 smtp-gateway2.carleton.ca ESMTP Sendmail 8.15.2/8.15.2; Wed, 16 Nov 2016 15:56:26 -0500 EHLO **********.ca 500 5.5.1 Command unrecognized: {EHLO **********.ca" EHLO **********.ca 250-smtp-gateway2.carleton.ca Hello [XXX.XXX.XX.42], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-EXPN 250-VERB 250-8BITMIME 250-SIZE 36700160 250-ETRN 250-STARTTLS 250-DELIVERBY 250 HELP

– J.Houston
Nov 16 '16 at 20:59






When I run a telnet session from my computer (which then uses the other public IP I get the following): 220 smtp-gateway2.carleton.ca ESMTP Sendmail 8.15.2/8.15.2; Wed, 16 Nov 2016 15:56:26 -0500 EHLO **********.ca 500 5.5.1 Command unrecognized: {EHLO **********.ca" EHLO **********.ca 250-smtp-gateway2.carleton.ca Hello [XXX.XXX.XX.42], pleased to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-EXPN 250-VERB 250-8BITMIME 250-SIZE 36700160 250-ETRN 250-STARTTLS 250-DELIVERBY 250 HELP

– J.Houston
Nov 16 '16 at 20:59














OK, that's the correct server. So now we can be sure that the problem is on your local computer or network. You can see that some additional characters were sent before your first EHLO.

– Michael Hampton
Nov 16 '16 at 21:08





OK, that's the correct server. So now we can be sure that the problem is on your local computer or network. You can see that some additional characters were sent before your first EHLO.

– Michael Hampton
Nov 16 '16 at 21:08










1 Answer
1






active

oldest

votes


















0














I think the problem is the active telnet mode that is standard in puTTY
I had the same problem with puTTY then I changed the configuration under telnet from active to passive and it worked.






share|improve this answer























    Your Answer








    StackExchange.ready(function()
    var channelOptions =
    tags: "".split(" "),
    id: "2"
    ;
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function()
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled)
    StackExchange.using("snippets", function()
    createEditor();
    );

    else
    createEditor();

    );

    function createEditor()
    StackExchange.prepareEditor(
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader:
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    ,
    onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    );



    );













    draft saved

    draft discarded


















    StackExchange.ready(
    function ()
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fserverfault.com%2fquestions%2f815363%2fi-have-to-input-helo-ehlo-commands-twice-before-it-registers-on-receiving-server%23new-answer', 'question_page');

    );

    Post as a guest















    Required, but never shown

























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    0














    I think the problem is the active telnet mode that is standard in puTTY
    I had the same problem with puTTY then I changed the configuration under telnet from active to passive and it worked.






    share|improve this answer



























      0














      I think the problem is the active telnet mode that is standard in puTTY
      I had the same problem with puTTY then I changed the configuration under telnet from active to passive and it worked.






      share|improve this answer

























        0












        0








        0







        I think the problem is the active telnet mode that is standard in puTTY
        I had the same problem with puTTY then I changed the configuration under telnet from active to passive and it worked.






        share|improve this answer













        I think the problem is the active telnet mode that is standard in puTTY
        I had the same problem with puTTY then I changed the configuration under telnet from active to passive and it worked.







        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered May 21 at 8:37









        nomisnomis

        1




        1



























            draft saved

            draft discarded
















































            Thanks for contributing an answer to Server Fault!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid


            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.

            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function ()
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fserverfault.com%2fquestions%2f815363%2fi-have-to-input-helo-ehlo-commands-twice-before-it-registers-on-receiving-server%23new-answer', 'question_page');

            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            How to write a 12-bar blues melodyI-IV-V blues progressionHow to play the bridges in a standard blues progressionHow does Gdim7 fit in C# minor?question on a certain chord progressionMusicology of Melody12 bar blues, spread rhythm: alternative to 6th chord to avoid finger stretchChord progressions/ Root key/ MelodiesHow to put chords (POP-EDM) under a given lead vocal melody (starting from a good knowledge in music theory)Are there “rules” for improvising with the minor pentatonic scale over 12-bar shuffle?Confusion about blues scale and chords

            What if the end-user didn't have the required library?What is setup.py?What is a clean, pythonic way to have multiple constructors in Python?What does Ruby have that Python doesn't, and vice versa?What is the reason for having '//' in Python?How do I create a namespace package in Python?How to package shared objects that python modules depend on?setuptools vs. distutils: why is distutils still a thing?Navigation in Windows 10 vs code not going to virtualenv library when the same library is installed at user levelPython create package for local usePackaging a project that uses multiple python versionsWhy is permission denied on pip install except for when “--user” is included at end of command?

            Esgonzo ibérico Índice Descrición Distribución Hábitat Ameazas Notas Véxase tamén "Acerca dos nomes dos anfibios e réptiles galegos""Chalcides bedriagai"Chalcides bedriagai en Carrascal, L. M. Salvador, A. (Eds). Enciclopedia virtual de los vertebrados españoles. Museo Nacional de Ciencias Naturales, Madrid. España.Fotos