Sam Hudson, a cyber intelligence and operations analyst at the CSC, said between the announcement of the move to Junara in October and mid-December, up to 40 Manx.net accounts had been compromised.
That marked a spike when compared to the total of 100 throughout the year in 2024.
The scams had left victims “shocked” and “quite a few people feeling bad that they had been misled” after their account had sent out “all these gift card scams to their contacts, with some people having bought them”, he said.
He said it was important that members of the public did not put any weight on who was sending an email, and if the correspondence was unexpected and included links or attachments it should be considered suspicious.
“Manx Telecom has warned customers that they and Junara would not send out emails with links in them,” he added.
Those who receive suspicious emails have been urged to report them to the island’s Cyber Security Centre.
He said: “For Manx.net users, if they are receiving phishing emails which are going to their main inbox, and if they are not comfortable with being able to identify them, it might be better to allow the account to close and move to a new email.”