REcipient verifycation

Hello,

Maybe a suppid question, but can I config gwia 2014 r2 in a way to check if the recipient exist in groupwise?
So I could filter incomming mail and block mails for non existing users by the spamfilter that can use smtp recipient address verification.


Thanks.

Tags:

  • Hi,

    There are no stupid questions here ;) Thanks for asking your question.

    It is my understanding that the GWIA automatically does address lookup by quering it's hosting domain to see if the address is valid or not. If there is no matching address internal to the GroupWise system the address is rejected.

    Perhaps tell us more about the spam filter you are wanting to implement in front of your GWIA so we can advise you further.

    Cheers,
  • Hello,

    I'm looking te same way postfix and other smtp server can react.
    When an mail comes in, the email (receiver) will be checked into the post office and if the email is invailid, an 5xx error is presented to the previous server. t
    The body of the mail isn't send at that moment, only if the receiver is know at that domain.

    So when rcpt to is done, the rcpt is looked up.

    So can a spamfilter know if the icoming mail is valid. If the email doesn't exist, no quarantine must created.




    laurabuckley;2454784 wrote:
    Hi,

    There are no stupid questions here ;) Thanks for asking your question.

    It is my understanding that the GWIA automatically does address lookup by quering it's hosting domain to see if the address is valid or not. If there is no matching address internal to the GroupWise system the address is rejected.

    Perhaps tell us more about the spam filter you are wanting to implement in front of your GWIA so we can advise you further.

    Cheers,
  • Hi,

    Sorry for the incredibly slow response :(

    If I understand you correctly, you don't want the spam filter/appliance to accept the message before the spam filter/appliance has done an address lookup on the GWIA to see if it is correct or not? If so then I do not know how to achieve this using Postfix or similar.

    Apologies. Perhaps more knowledgeable people in these forums will come across this thread and assist you.

    Cheers,
  • Am 12.04.2017 um 21:56 schrieb rniesen:
    >
    > Hello,
    >
    > I'm looking te same way postfix and other smtp server can react.
    > When an mail comes in, the email (receiver) will be checked into the
    > post office and if the email is invailid, an 5xx error is presented to
    > the previous server. t
    > The body of the mail isn't send at that moment, only if the receiver is
    > know at that domain.
    >
    > So when rcpt to is done, the rcpt is looked up.
    >
    > So can a spamfilter know if the icoming mail is valid. If the email
    > doesn't exist, no quarantine must created.



    Groupwise behaves exactly the same way since VErsion 6.0. Non-existing
    email addresses produce a 5XX Error. I wonder why you ask, didn't you
    try it?

    CU,
    --
    Massimo Rosen
    Micro Focus Knowledge Partner
    No emails please!
    http://www.cfc-it.de
  • Hi,

    we are using postfix as a smtp relay as antispam with spamassassin, amavis, postgrey etc. infront of the gwia for several years now. with this you can block mails before they even get downloaded by postfix and forwarded to gwia.

    if you have ldap auth for groupwise you can automatically fill the relay_recipients file with existing gw users via perl script.
  • Hi,

    Many thanks for this information. My question for you is how do you deal with Nicknames and Distribution Groups?

    Looking forward to hearing back from you.

    Cheers,
  • laurabuckley;2455971 wrote:
    Hi,

    Many thanks for this information. My question for you is how do you deal with Nicknames and Distribution Groups?

    Looking forward to hearing back from you.

    Cheers,


    hi,

    for nicks and dist groups i would use virtuals. those have to be added manually. maybe it's possible to use rest and curl for adding the needed information to postfix by script. havent tested it yet.
  • Hi,

    Thanks for the information and feedback. Much appreciated.

    Cheers,
  • Hello,

    Let me tell how it could work :)

    220 xxxxxxxxxxxxxx ESMTP Smtpd; Wed, 3 May 2017 11:40:58 0200
    ehlo test.com
    250-xxxxxxxx Hello yyyyyyyyyyyyyyyy [zzz.zzz.zzz.zzz], pleased to meet you
    250-ENHANCEDSTATUSCODES
    250-8BITMIME
    250-SIZE 25600000
    250-DSN
    250-AUTH LOGIN PLAIN
    250-DELIVERBY
    250 HELP
    mail from:<test@test.com>
    250 2.1.0 <test@test.com>... Sender ok
    rcpt to:<bla@1stsolutions.be>
    550 5.1.1 <bla@1stsolutions.be>... User unknown

    Now I'm using a ldap query, but for doing this, I have to open 389.
    Exchange can do the smtp verifuciation directly.

    So can gwia to smtp verifycation.
    So if I do rcpt to:<someone@somedomain> and the user doesn't exist, gwia returns 550 user unknown.
  • Hi,

    Yes, GWIA returns 550 user unknown by default.

    Cheers,