A super-fast sorting computer and a team of address dectives are making lightning quick decisions as they file through your Christmas mail this year.

Some MPs have claimed that the public should not use red envelopes as they are harder to read and will be sorted slower.

‘Don’t use red envelopes for Christmas cards’: MP’s call over festive post

But Royal Mail say that they can deal quickly with all properly addressed post, whether red, blue or gold.

An Intelligent Letter Sorting Machine reads the addresses on letters at hyperspeed when they are first received in a sorting office. It makes split-second decisions about where to send the mail in the office.

But in the event it can not read your handwriting a team of 'address detectives' is on hand to help.

The ISLM emails a photograph of any mail it cannot read - about five per cent - to the teams, who use their human eyes to read the addresses, dealing with thousands of images an hour.

A spokesman for Royal Mail said: "As the universal service provider, Royal Mail is proud to deliver the Christmas post for consumers and businesses.

"Our Intelligent Letter Sorting Machines can process up to 50,000 items an hour.

"Anything the machines are unable to read are almost instantaneously passed through to our data centre where our team of ‘address detectives’ identify the correct address.

"There is no impact on the delivery timescale for the customer. Customers are welcome to use any form of envelope or ink for their Christmas cards.

"The only advice we always offer - is to always use the postcode."

A spokesman said to disregard old advice on its website asking the public to post a white label on a red envelope.

The Royal Mail has recommended a series of last posting dates to ensure people get their cards in time for Christmas – second class is December 18, first class December 20 and special delivery, December 23.