It also scans for viruses which, like the Melissa virus, leave a footprint in the message headers or envelope, Hodges said.

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After extensive research, the fire service decided that condoms - rather than pens, rulers, etc - packaged in a cardboard envelope bearing the core message, had the best novelty factor and the ability to communicate a wider safety message.

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An icon shaped like a tiny envelope appears on the display, indicating that a message is waiting.

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