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An authorized domain authorized-domain.tld in exchange 2010 with main domain main-domain.tld would not send email to internet but internally to main domain.

Reproduced / describde scenario:

  1. User opens outlook client 2010 and binds the authorized domain email account e.g.: authorized-email@authorized-domain.tld
  2. After account loaded and from this account, user then composes an email to external@somewhere-in-internet.tld and internal@main-domain.tld
  3. Then user send the composed email to both email-adresses
  4. Lastly user gets only from the email external@somewhere-in-internet.tld an NDR from the NoSpamProxy Gateway with following code #550 5.4.4 Unable to relay ##

I have checked out the NoSpamProxy rules and also the send connectors of exchange 2010 to the internet, but nothing suspect out there.

I suspect a missing DKIM selector (could not find one selector for authorized-domain.tld on main-domain.tld TXT records) that should allow exchange 2010 Server with the main domain main-domain.tld to send emails externally as authorized-domain.tld, since MX record for authorized-domain.tld accordently points to main-domain.tld.

Do you have any ideas on this one, am i right or am i missing something tho ?

Thanks for checking out!

Manifest Man
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  • 1. How did you add this authorized domain(***authorized-domain.tld***) to your organization? Is the process like the following? **Add authorized-domain.tld to DNS suffix** -> **Add this domain to accepted domain** -> **Create an email address policy with this domain** -> **Use this domain suffix for your mailbox(Email Address and UPN)** 2. Could you use this authorized domain to successfully send emails to another external email address(e.g. outlook.com, gmail etc.)? – Ivan_Wang Nov 01 '21 at 02:38
  • 3. What're the configurations of your send connector?(If you attach them, please don't forget to alter any sensitive info.) – Ivan_Wang Nov 01 '21 at 02:42

0 Answers0