? infected file deleted

Tonight I received a warning from avast! followd by an email.
the subject of the email was avast! heuristic - WARNING

iframe tag found, it may be dangerous

It concerned an item named “Offer: Love is in the air” sent to my address via email@member.wanadoo.co.uk
I chose the option to delete immediately. Do I need to take any further action?
A contact who opened the file found that her AV has gone spontaneously on to scan.
Should I take any further action?

No that should take care of it, I would check that you clear any emails in your deleted emails folder.

For peace of mind you could run a scan of your HDD, although this is probably unnecessary.