ISS Information Systems & Services - Rejected Mail Blacklist

The DNS Blacklists are responsible for most of the mail we reject. These lists work on the basis that spammers use specific ip address to send their millions of mails. These ip addresses are stored in central blacklists. When we receive a mail we check its origin against these lists. If it is on a list we reject it.

Which Blacklists do we use ?

There are a large number of these type of lists available. The lists we currently use are below. rbl-plus and spamhaus are paid services which are kindly provided through our service provider: http://www.heanet.ie/services/anti-spam

Check if you are on any Blacklists

You can check if you are on any blacklists here: http://www.mxtoolbox.com/blacklists.aspx
If you are on one of these lists other organisations may also block your mail.
We can not correct this - you must inform your mail administrator.