My covid recommendations based on own experiences and what I am being asked most at Where frost reign.
The logistics and transport system is heavily burdened worldwide and in some places it has collapsed. From Norway today, there are 22 countries that it is impossible to send registered packages to. Out of 196 countries in the world, I can send mail to 86. In addition to strained delivery options, the online retail business has experienced phenomenal increase. I haven't checked the numbers in a while, but last I made a dig we were talking about 25% in Norway alone. I expect it to be the same in other countries. Furthermore, the pandemic has caused plane cancellations and forced mail to be redirected by wheels across countries and continents. The exploding market and continuing alterations of cross-country travel restrictions has again caused a shortage of delivery vehicles. This is the reality of the current shipping situation now.
If you are concerned about secure delivery of your mail I recommend taking the extra cost and opt for registered and insured mail.
In cases where you do not have registered and is expecting standard letters that cannot be tracked, I recommend contacting your domicile post agent or check their web page re updates on the post and corona situation, delays, etc. Every agent have this information displayed and is updating as the situation progress. In some situations you might have to search a bit to locate information. If it is not readily displayed in your post agents web page - use an online search engine. In instances like this, seller/sender cannot provide you with any information as the letter was not shipped as registered letter or package. A little research will save you time and a lot questions. For sellers/senders in these instances I recommend to keep all your postal receipts. You might need to document orders are shipped at a later date.
Delays are to be expected. In worst cases I see across the line that post estimated to have a transit of a week, may take a month. So be patient and do your research re your local delivery situation. Some countries are blocked on the receiver end and shipping list. Sender should have the overview here, but it if you are ordering online it is also your own responsibility at the moment to know if you can receive goods. Should you be unlucky the order is not lost, but it will be heavily delayed until borders re-open.