Next week we will be making a change to our incoming email servers which is aimed at reducing the amount of spam email from reaching customer's mailboxes.
Historically, we've been purposefully cautious of rejecting email outright and prefer the method of marking messages as spam based on a 'spam score'. Customers have options as to what score to mark and to reject messages. However, due to the high number of spam messages, the cost of scanning each message and the extremely low risk of false positives we're going to introduce rejecting messages from IP addresses that are known spammers.
Specifically, the change is to reject messages from email servers that are listed in the "Spamhaus" block lists. These lists contain IP addresses that are known to be spam senders or are compromised machines in some way. Spamhaus have "a long-held reputation as having a false positive rate so low as to be unmeasurable and insignificant".
Many mail servers around the world use these same block lists, but if you are in anyway concerned about this then please to get in touch with us.We are making these changes at the moment. (Wednesday afternoon). As described above, we're not expecting this to impact customers in a negative way.