Xtra has joined the battle against spam with the launch of its own spam filtering service.
Based on anti-spam giant Brightmail's service, the Xtra spam filter is free to all customers from today, says the head of internet and online marketing Chris Thompson.
Customers are given the choice of receiving all their email with potential spam marked as such, have the email marked as spam sent to a separate folder automatically or having it blocked outright.
"We wanted to give customers the choice in that matter. For some it's important they see every piece of email and make the decision themselves. For others they just don't want to see the spam at all."
Thompson says the service will need to gain the trust of some customers so they're comfortable with its capabilities and confident they're not missing out on genuine emails.
"Brightmail has one of the lowest false positive rates around, which is one of the reasons for choosing it."
TelstraClear also runs Brightmail's anti-spam service, but Thompson says he hopes Xtra will avoid the issues that have plagued TelstraClear's implementation.
"We're running a different implementation from what we understand TelstraClear is offering. Ours is the latest version and we've also got a much larger mail load so we've scaled the mail servers to cope with excess traffic."
TelstraClear's public affairs manager Mathew Bolland says the company's implementation of Brightmail is the latest version and that Xtra is simply trying to distract from having been late to market with the same product.
"The only difference between Xtra's implementation and ours is that our customers were protected two months earlier than Xtra's customers."
Bolland says the Brightmail service being run at TelstraClear is the latest version of the software and offers users the same coverage as Xtra's version.
Xtra currently clears around 3 million emails a day. Thompson says the mail servers have an overhead that allows for more than double that traffic. Thompson doesn't anticipate any degredation to the Xtra email service because of the new filter.
As well as TelstraClear and Xtra's services, a number of other ISPs offer anti-spam filtering as well, including Ihug and ICONZ. Thompson says with so many offering the service, New Zealand has become one of the most highly covered email nations on the planet. Brightmail's system makes use of dummy email accounts set up with each ISP that uses the service to catch spam mailouts as they're happening.
"We are setting up drop boxes for users to forward their spam to so we can learn from what's going on out there."