A local anti-spam product that's getting international attention, MailWasher, is about to get an upgrade that should ease network operators' minds.
MailWasher uses heuristic analysis to rate emails to determine if they are spam, but users can also use a "bounce" option to reject spam manually, making it look as if the email were rejected by the network administrator mailer daemon rather than from their own address.
Unfortunately many spammers spoof the sender's address and users hitting the bounce button simply clog up administrator's out-bound email servers with undeliverable mail.
In May a number of network operators complained to the network operators group mailing list (NZ NOG) about customers using MailWasher in breach of many ISPs' terms and conditions by changing the header information.
Simon Lyall senior network administrator for Ihug, says using the bounce facility in MailWasher can affect the delivery of real mail for other customers.
"We have two lots of mail servers - one is our main server, SMTP.Ihug, and we have one other that just handles bounces. What happens is SMTP is optimised to get emails out as fast as it can. It retries every few minutes. If there are a few hundred of these MailWasher emails and it has to retry them every time it comes around, that slows down normal customer email."
Now the software is about to be updated and the man behind MailWasher, Christchurch-based Nick Bolton, says it shouldn't be a problem in future.
"We're adding a direct SMTP email sending facility and also some smarts that will tell it if the sender's address is fake."
Testing on the new version should be finished by Friday and Bolton hopes to have the the software ready by the beginning of next week.
The new version will also include support for Hotmail accounts, and Bolton says more features will be added later in the year.
Bolton, who has a maths and finance background rather than software development, decided one day he'd had enough spam and contacted a local software developer in Christchurch to see what could be done.
"I'm more of an ideas man myself - they've been really good at coming up with ways to implement the ideas." The software was designed and built by eCOSM and the company is also working on the upgrades.