As I understand it -- primarily from TED Talks -- corruption in India is endemic and somewhat expected. Sure, it's a form of racketeering, in the sense that many government employees have to give their boss a cut, and if they don't, they will be replaced by someone who does. It's typically presented as an "expiditing" fee.

And the cause there, as presented by Wikipedia[1] is fascinating to contemplate. The abnormally high tax rate (especially compared to the services provided) increases the demand for corruption to avoid taxation. Taxation avoided reduces money available for bureaucrat salaries, to where they are almost reliant on the bribery system to make ends meet. And hence the pressure on line staff to kick back money up -- a promotion would separate you from direct contact with the public and represent a loss of income that must be replaced somehow. It's kind of a weird Laffer curve phenomenon where higher tax rates yields less revenue.

[1]: https://en.wikipedia.org/wiki/Corruption_in_India#Factors_co...

It sounds like it would act as an incentive for important mail to arrive safely and promptly, if the delivery agent benefits personally.

> they could also easily "lose" the package?

And they often do.