LibEtPan
The purpose of this mail library is to provide a portable, efficient framework for different kinds of mail access: IMAP, SMTP, POP and NNTP.
It provides an API for C language.
是这个吧,看了下,这个应该是直接可以用msys2的autotools编译的。不过要是直接放到qt pro里还是需要好好分析下vc的工程结构。