How can I use tcpwrappers in conjunction with Exim?
A0705: Exim’s own control facilities can do all that tcpwrappers can do. However, if you are already using tcpwrappers for other things it might be convenient to include Exim controls in the same place. First of all, ensure that Exim is built to call the tcpwrappers library, by including USE_TCPWRAPPERS=yes in Local/Makefile. You also need to ensure that the header file tcpd.h is available at compile time, and the libwrap.a library is available at link time, typically by including it in EXTRALIBS. You may need to copy these two files from the tcpwrappers build directory to, for example, /usr/local/include and /usr/local/lib, respectively.