Enable TLS with Build

To enable TLS in sendmail you need to add two new lines to your Build m4 file:

APPENDDEF(`conf_sendmail_ENVDEF', `-DSTARTTLS')
APPENDDEF(`conf_sendmail_LIBS', `-lssl -lcrypto')

With these two lines in place, build a new sendmail. If you get an error such as the following:

tls.c:16: openssl/err.h: No such file or directory

you will need to let Build know where you installed the ssl components:

APPENDDEF(`confINCDIRS', `-I/opt/packages/openssl/include')
APPENDDEF(`confLIBDIRS', `-L/opt/packages/openssl/lib')

Here, we installed OpenSSL in the nonstandard path /opt/packages/openssl.

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