Telstra is investigating a mail delivery issue that has blocked emails to hundreds of its home internet customers since the weekend.
Emails to affected Telstra customers bounced back, with the senders receiving failed delivery status notification messages.
A Telstra spokesman said the issue affected “low hundreds” of the “millions” of email addresses on Telstra’s BigPond network.
“Since the weekend we have been alerted to reports that mail to a small number of BigPond customers has been not been getting through,” he said.
Posts on broadband forum Whirlpool indicated that the issue stemmed from a BigPond server being listed on realtime spam blacklists.
Telstra’s spokesman said the issue was “under full investigation” and staff were checking affected email addresses.
“We apologise for any inconvenience and hope to have the cause identified quickly and full services restored for those affected customers,” he said.