Tiscali says it has restored email service for many customers who lost out after spammers managed to commandeer the company's mail servers.
Spammers last week managed to overcome security protections on the Italian ISP's computers to send large amounts of junk mail, resulting in many destination service providers barring mail from Tiscali users.
Although the ISP was able to respond to a spike in customer complaints it received last week, it said on Wednesday it could take another seven to 10 days before the many destination servers operated by other ISPs dropped the barriers they had introduced to block mail from Tiscali customers.
A service update from support staff last night suggested the problem was now almost cured, however.
"Tests throughout today, and feedback from customers, indicate a significant improvement in our outbound email service," the update read. "We believe the service is now largely back to normal.
"Test mails sent to all major email providers have gone through successfully with the exception of AOL. This is under investigation and we will update [on Friday] on progress."
The episode has been an embarrassment for Tiscali, which previously acquired World Online, LibertySurf and the UK's LineOne ISPs. The company now offers telephony and even broadband IPTV services, but was forced to recommend free, web-based email alternatives to disgruntled customers this week.
Technicians installed new hardware and tweaked settings and the firm's SMTP server is now running at 80% capacity.