Our email platform supports the use of DNS RBL's, our agents and end-users have the ability to enable a range of premium services to control the email they receive Some of these services include the checking of internal blacklists and external DNS RBL's.

Mail being rejected with a message "554 Service unavailable; Client host [XXX.XXX.XXX.XXX] blocked using YYYY" indicates the mailserver sending mail to our network is listed on the YYYY DNS RBL. If you're receiving a message like this you will need to contact your IT department or ISP and have them resolve the issue. There is nothing we can do as we have no control over the DNS RBL's. The above message will be suffixed with a URL which should be followed for more information.

Mail rejected with a message "Security Incident #XXXX" indicates our abuse department has explicitly setup a block to prevent mail with certain criteria entering our network. If you're receiving a message like this you will need to contact your IT department or ISP and have them resolve this issue with our abuse department.

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