
When I look at the commands regarding POP3 (see also links below), libcurl's functionality seems to be limited here. According to my research so far, even in C/C++ there is no example for retrieving all emails at once without logging into the server for each mail.
Even Stenberg's manual does not provide any useful information here.
After you maintain this topic, you might have a tip for an example in C, C++, PHP or a corresponding link ?
https://everything.curl.dev/usingcurl/reademail.html
https://curl.se/libcurl/c/example.html
https://github.com/curl/curl/tree/master/docs/examples