I have an Exchange Server 2010 std. edition. It was all working fine for almost 10 months and suddenly what happened is, any mails coming from outside was rejected
The sender receives the following message:
Delivery has failed to these recipients or groups:
'User Name (email@example.com)'
Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address may only accept e-mail from certain senders, or another restriction may be preventing delivery.
The following organization rejected your message: firstname.lastname@example.org.
Diagnostic information for administrators:
Generating server: servername.abc.com
receivingservername.domain.com #550 5.7.1 Recipient not authorized, your IP has been found on a block list ##
No changes been made to the receive connector except for the permission groups which has all the options checked except Partners. This change was done after the installation of the exchange on the default receive connectors.
Since I was not receiving emails, I did checked my firewall, spam suite and nothing seems to have problem, as I continue to have the problem even after disabling the spam suite.
Finally, I created a new custom receive connector, set the IP address as local IP with port 25. Checked only the Externally Secured (IPSec) option under the authentication and permission group as default, by this I started getting emails, but the sad part is, I get to lots of spammers in the mail queue and looks really ugly. When the newly created connector is disabled, removing the spam domains in the queue, it looks fine but unable to receive mails and again when enabled, all goes for six...
I have another domain in my office with exchange 2010, I copied the same settings for the receive connectors (on the default ones created during exchange installation), but doesn't work. Works only when I enable the new connector.
Your resolution is highly appreciated.