 In the 21st century, postal services are much more than letters and stamps. The postal sector is a pillar of a country's socioeconomic infrastructure, reducing transaction costs and facilitating the exchanges of goods and communications. The postal sector is thus a key contributor to the achievement of the United Nations Sustainable Development Goals, SDGs. Yet the world is going through a challenging phase, as the battle against COVID-19 redefines the world economy and accelerates transformation everywhere, including in the postal sector. With the pandemic, postal operators had to deal with intermittent air traffic, labour supply shortages and increased operational costs. Unlike other sectors, they also had to continue operating during most lockdowns, easing the delivery of surging e-commerce sales. In spite of its essential nature, the sector had been facing tremendous challenges even before the pandemic, with a decoupling between postal revenues and economic growth, as well as growing gaps in development between and within regions. Postal networks are considered to be developed if they ensure a reliable service, benefit from good connectivity, enjoy a high level of demand from citizens and have operations that are resilient to shocks. The Integrated Index for Postal Development to IPD, developed by the Universal Postal Union UPU, encapsulates this definition and provides policymakers, regulators and operators with tools to assess a country's level of postal development across four dimensions – reliability, reach, relevance, resilience. Capitalising on a wealth of big data and statistics, the UPU's 2021 Postal Development Report contains the latest two IPD ranking, covering 168 countries. Switzerland retains the top spot thanks to stellar performance across all dimensions, including improvements in reach and resilience. Germany comes second thanks to progress in reach and superior performance in reliability and relevance. Austria is third thanks to a balance showing across all the four pillars in spite of the many logistical turbulences caused by COVID-19. There have also been some encouraging results across the UPU's regions. In spite of the encouraging results of such leading countries, gaps in postal development are intensifying everywhere. In addition, the reaction of postal operators to the COVID-19 crisis has greatly differed, although nearly all have had to rethink their systems of delivery. This transformation is particularly visible in the reliability dimension of the two IPD. Following the pandemic, average domestic delivery times have increased by 12% compared to 2019. In 2021, there are visible improvements, but more time will be needed before declaring a return to normal. Although the crisis is still not over, there are also grounds for more positive perspectives. eCommerce continues its ascent, constituting a reservoir of opportunities for all participants in postal markets. Thanks to a well-established global network across 192 nations, postal operators can also attempt to bank on the growth prospects offered by their international business. As a specialised agency of the United Nations system, the UPU can support governments, regulators and postal operators in their journey towards greater postal development and the achievement of the UN SDGs. And the two IPD is a great addition to their toolbox.