A postal strike means disruption for the public, for businesses and their consumers. But not everyone dreads industrial action.
The Royal Mail is the nation's largest postal service
The lack of activity by the Royal Mail means that other postal delivery companies, such as couriers, are given a rare chance to fill the void, unchallenged by the nation's main postal provider.
Robin Mackintosh is business development manager for Fast Lane International, a courier service based in Maidenhead, which delivers globally.
He said the company's trade "absolutely" benefits from any industrial action by the Royal Mail.
"It's beneficial to the courier trade in general when there's a postal strike and we as a company gain long-term business from that situation.
"It's clearly beneficial to us but chaotic for everyone else.
"Without taking a swipe at Royal Mail, when people see the benefits they reap from speed, trackability and value for money then they often use our services again."
Mr Mackintosh said his company made "thousands" of deliveries a week, and that during a postal strike there would be a 60% increase in inquiries each day.
"Of that, we would expect to retain about 40% of people. These days the public is much more aware of the different services available and are willing shop around.
"We do have some people getting in touch who want to make sure a birthday gift is delivered on time, but since the recent upsurge in eBay traders we have people who don't want their feedback on the website affected."
A spokesman for the British Chamber of Commerce echoed Mr Mackintosh's comments, saying it had "anecdotal" evidence that courier firms benefited from postal strikes.
"Businesses need to get cheques out in the post.
"What solutions have they got? This is the only solution for the next few days.
"Our advice to courier firms is to get out there, because you're knocking on open doors."
However, a strike by the Royal Mail does not necessarily mean an upturn in trade for alternative postal delivery companies.
Guy Buswell is chief executive officer of Birmingham-based Business Post Group, which also runs UK Mail - this branch of the company delivers 6m-8m items of mail per day.
However, the final delivery is carried out by the Royal Mail, which is sub-contracted by Business Post.
Mr Buswell believes that "no-one benefits" from a postal strike.
"99% of all mail is delivered by the Royal Mail, so if they strike, 99% of all mail is not delivered.
"Couriers are not designed to deliver mass mail. If you give a courier 100 addresses to get round in a day, then he won't have time.
"Also, delivery will cost 20 or 30 times what it would if you were using the Royal Mail.
"Some companies will often get swamped with inquiries but will only deal with existing customers, not new ones, because they don't have the ability to cope with the increased demand.
"In the long term, mail gets a bad name."
Nick Murray of TNT, which delivers mail between businesses, says that the strike will not affect its orders.
"We deliver parcels but operate in a business to business environment, not personal deliveries. So a Royal Mail strike doesn't have a great effect on our business.
"The parcel business side of Royal Mail is Parcel Force, and that's generally unaffected by the strike. So if a business wants to send a parcel, it will still do what it normally does."