Which ports needed to be opened for SMTP Server?
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Thread: Which ports needed to be opened for SMTP Server?

  1. #1
    Junior Member
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    Which ports needed to be opened for SMTP Server?

    Hi ,
    I'm new to this thing. I 've to set up SMTP server to send outgoing mail for my company. i've tried to setup SMTP server that came with Widows 200 server but i've got
    an error message :
    550 Unable to relay for customer@mail.com
    so I think this 's because firewall has blocked it.


    what 're the ports both incoming and outgoing needed to be open ? and could you give me a link to really good tutorials of how to set up SMTP server .

    thanks for helping.

  2. #2
    Banned
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    Port 25, normally.

  3. #3
    Junior Member
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    Thanks Katja that problem 's solved now .

    But there's new problem. My SMTP server's behind the firewall . So every message trying
    to send is cannot reach the destination . all of them were put on to the bad mail folder .
    in inetpub\mailRoot\Badmail.
    I wonder what to check or to configure.

    thanks

  4. #4
    Senior Member
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    Hi

    that problem 's solved now .
    Question: How did you solve it?


    Within the SMTP rfc[1], 550 is a generic error code for a "RCPT Failure"
    reply. Usually, the mail server specifies the failure with more details,
    e.g. "Unable to relay for ...".

    In this particular case, the error is most likely caused because the mail server
    did not recognise you as an authorised user.

    You tried to use the mail-server[2,3] to send an email to an external
    email-address without proper authentication (if you would be able
    to do so, the mail-server would be known as an "open relay").
    This is the reason for my question. I would like to avoid your
    mail server to be blacklisted[4].


    Cheers

    /edit: your mail server needs SMTP (delivery) outgoing and incoming (Port 25)
    In addition, POP3 (Port 110) may be needed.
    If you are behind a router, make sure that the necessary ports are forwarded
    to your mail server. But still, be sure you understand what you are doing
    before opening the port to the public.


    [1] http://www.ietf.org/rfc/rfc0821.txt
    [2] http://www.microsoft.com/technet/pro...87a2b88f2.mspx
    [3] http://support.microsoft.com/kb/q230235/
    [4] http://www.ordb.org/
    If the only tool you have is a hammer, you tend to see every problem as a nail.
    (Abraham Maslow, Psychologist, 1908-70)

  5. #5
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    Question: How did you solve it?
    while i'm waiting for this thread's reply. i'm trying to search google at the same time , and i found the solution in microsoft kb's (the second link exactly) . and i put my client's ip in the Relay restictions .

    But all the message trying to send is return by the demon.

    :
    " Delivery to the following recipents failed.

    customer@email.com
    "
    i made sure the email is valid and my SMTP server can connect to Internet with properly configured DNS lookup.


    i search the google around and come up with these questions :

    1. what's the Smart host ?
    2. Can IIS SMTP Virtual server send E-mails without forwarding them to Smart host?
    3. If can how to configure it ? or how to test if it can send email?
    4. May be it's because of firewall ? because my SMTP server is under heavily firewall, so i need to know whichports exactly need to be opened beside port 25, both incoming and outgoing.

  6. #6
    Senior Member
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    Hi

    Hmm...Smart host, Relay hosts are terms usually referring to servers,
    which are allowed to send emails to the public (smart host) or send emails
    to the corporate mail server (relay host). In this context, the smart host
    and relay host are in a different "zone" than the corporate servers,
    e.g. DMZ (smart host, relay host) and LAN (corporate server).
    The goal is to separate hosts facing the internet from the "inner" LAN.
    (edit: oh god, sloppy 5' language... )

    Any mail server should be able to send emails without this kind of extra
    configuration. Again, be sure you got protection from the managment,
    when you are setting up a mail server for your company...

    Try first to send an email to a local account, using a local account.
    Test the connection "to the Internet" by establishing a connection
    to a known mail server on port 25, which is the only port required
    at the moment.

    Good luck

    Cheers
    If the only tool you have is a hammer, you tend to see every problem as a nail.
    (Abraham Maslow, Psychologist, 1908-70)

  7. #7
    Junior Member
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    Try first to send an email to a local account, using a local account.
    Test the connection "to the Internet" by establishing a connection
    to a known mail server on port 25, which is the only port required
    at the moment.
    Thanks now it seems like my SMTP Server cannot connect to any mail server on port 25 so it cannot send e-mail to the internet . So i'm going to request to the network guy to open port 25 for my server and i hope that will make the server to be able to send mails to internet ...

  8. #8
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    after open port 25 i still can not send mail .
    It said delivery failed...

  9. #9
    AO Curmudgeon rcgreen's Avatar
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    It depends on what you are trying to accomplish. If you have a normal
    consumer type internet connection, broadband or dialup, through an
    internet service provider, you will probably need to set their mail server
    as your smart host, relaying all your mail through them like any other
    consumer/user.

    If, on the other hand, you have a permanent connection to the net,
    a fixed ip address and a domain name, your server should be able
    to send mail directly to most mail servers on the net, assuming that
    the mail is destined to a user on that server

    If you don't have a fixed ip address, many servers will refuse your connection
    due to increasingly strict spam filters.

    Look carefully at the error messages. Are they from remote servers
    refusing your connection or is it a firewall not letting you out.
    I came in to the world with nothing. I still have most of it.

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