"I personally apologize for any inconvenience that this has caused and I ask that you do not click on any of the links in those e-mails for security reasons."

While one link pointed to a rival e-mail hosting company, one local IT manager, who preferred to remain anonymous, said the second address would "almost certainly be a phishing site."

Hirst said the company is working with Kayako to resolve the issue.

The vendor was unavailable for comment.

Fortunately, Servers Australia data was not compromised although breaches have increased significantly in the past two years.