cc -O2 -Wall -Wno-narrowing -Iinclude -I`head -1 ../conf-qlibs`/include `head -1 ../conf-ssl` -I/usr/local/include

# This will work for both i386 and AMD64 architecture enabling INET6 support.
# IDN2 support is NOT enabled by default. You do not have 'libidns2' installed and set: -DIDN2

# For obfuscation, you can hide the virtual user's local part for VERP addresses; inappropriate for VPOPMAIL:

cc -O2 -Wall -Wno-narrowing -Iinclude -I`head -1 ../conf-qlibs`/include `head -1 ../conf-ssl` -DHIDEVIRTUALUSER

# qmail-remote will bounce mails immediately, if no DNS record is found; or mail may stay in the queue until it expires:

cc -O2 -Wall -Wno-narrowing -Iinclude -I`head -1 ../conf-qlibs`/include `head -1 ../conf-ssl` -DDEFERREDBOUNCES

# security might be enhanced, using the following compiler flags:

cc -Wall -pipe -z relro -z now -pie -fPIE -fstack-protector-all -D_FORTIFY_SOURCE=2 -O2 -DIDN2

# This is for gcc and with strong security in mind.