Postal staff have been out on London's streets throughout the pandemic, at all hours, in all weather.
Why then are Londoners complaining of weeks-long delays to their mail?
BBC London has obtained footage from a whistle-blower of letters dumped and left for days, and even weeks, in Royal Mail depots.
The frustrated postman has explained no cover has been brought in for staff sickness, so letters are just left to pile up.
Royal Mail has been contacted for comment.
BBC London has been reporting on the problems with post, particularly over the festive period, for the past couple of years.
The whistle-blower spoke to BBC London anonymously, for fear of losing his job, and said he felt the service was letting customers down because if somebody went off sick "those letters won't get done".
"It can go on for weeks," he said. "They'll just sit there - and this is where it gets frustrating- because you'll just see the work piling up every day."
The postie said that the more expensive tracked parcels were given a higher priority than ordinary post, despite the fact the normal mail, including insurance documents, bills and hospital appointments, may be more urgent.
He said: "All of those are being left aside for the sake of someone getting a box of brushes or a puzzle, or something like that, that had been sent tracked - because it was tracked it was prioritised over everything else."
Another Royal Mail employee told BBC London there were longer-term issues too, with postal rounds becoming unmanageably big.
They said this was due to computer algorithms being used to calculate routes without any human input on the impact of delays such as roadworks or building works.
Royal Mail has said Covid led to temporary staffing shortages in some areas, but targeted local support has been provided and most areas now have a normal service again.
