The new OpenSMTPD 7.5.0rc1 works well with LibreSSL on Slackware64 Linux.
My compile script uses CFLAGS and LDFLAGS like this: CFLAGS="... -I/usr/include/libressl" \ LDFLAGS="-L/usr/lib64/libressl -lcrypto -lssl \ -Wl,-rpath=/usr/lib64/libressl" \ ./configure \ ... It solves the git problem 1188, "configure: error: Your LibreSSL headers do not match your library". And it works even when I don't have LibreSSL installed and just have OpenSSL 1 installed. This version works on 32-bit Slackware: CFLAGS="... -I/usr/include/libressl" \ LDFLAGS="-L/usr/lib/libressl -lcrypto -lssl \ -Wl,-rpath=/usr/lib/libressl" \ ./configure \ ... Richard Narron