The only way for now is to look up the international mail suspensions. The PC postal monitor links to the official USPS site which updates when suspensions happen. Also people from PC constantly update.
Usps site doesnt currently have an option to recieve notifications
I personally check PC suspensions and then click the link that leads me to the official USPS site.
I also drew an official address to Belarus on the 1st of July and it has expired also. But I did not use a return address so I will not have it returned. How do you receive a refund from the USPS if you have no proof you sent it? I don’t think my local PO would take my word for it considering how they operate here. My carrier knows the postcards I send and receive from my mailbox, but I don’t know how she could become involved in it. Perhaps my card will still make it. Does anyone know when the first suspension began?
There is not a notification system set up on PostCrossing for service alerts. PostCrossing is a free service run by volunteer administrators in Portugal, and funded by donations and some advertising.
Adding a new feature to the PostCrossing website would require hiring someone to write the code, ensure it works properly, etc., which takes time and money.
Many of these mail delays and suspensions are due to a war, and a pandemic.
Perhaps you could program a reminder in your phone’s calendar to remind you to check for updates twice a week or so?
I have a card en route to Belarus as well, since early June, so the frustration is understandable.