Introduction of the additional layer of protection comes as the Internet provider moves to boost network capacity and block unwanted e-mails in the face of sharply rising volumes of messages, the dominant proportion of which are spam.
BigPond came under heavy fire last year when a sudden surge in e-mail volumes, attributed by the telecommunications carrier to spam and viruses, exceeded the capacity of the Internet provider's systems to cope and slowed e-mail traffic to the point that messages took several days to reach their intended destination.
However, BigPond managing director Justin Milne denied any link between the filtering protection and the telecommunications carrier's efforts to overcome those issues, saying the new move was "just part of business as usual".
Milne said the new filtering protection had been initiated by Telstra's spam network operations centre, a group which had introduced a raft of new processes to block the introduction of unwanted e-mails into the systems of Australia's largest Internet service provider.
The filtering, which will operate at the entry point of the BigPond network, is designed to supplement customers' personal computer security measures and BigPond's retail anti-virus and anti-spam products.
Milne cited the growing surge in e-mail traffic -- more than 60 percent of which were spam -- as requring "a very high level of vigilance and action by Internet service providers and Internet users".
Milne added that e-mail traffic to BigPond had grown by 30 percent since January this year, with around 19 million e-mails arriving in the BigPond network every day.
"Industry forecasts indicate that this rate of growth is set to continue," he said.
Milne clarified that the filters are not a cure-all and are not designed to check mail in customers' BigPond e-mail inboxes.
"These proprietary products, which are upgraded daily, are catching more than 98 per cent of viruses and about 95 per cent of spam," Milne said.
The first of several new measures to combat spammers misusing the Telstra Webmail service was also introduced this month.
The key measure was the use of 'fuzzy logic' during the sign-up stage for Telstra.com services. Customers will be required to identify letters presented in an image reducing the risk of multiple Webmail accounts being set up by spammers who use automated programs to set up bogus accounts.
Milne also said the provider was well advanced with plans to implement a new e-mail platform, with all new customers from July this year being provisioned on the new system.
The provider is also building a new billing platform, with new customers being provisioned on that system from July or August this year.