./compile qmail-remote.c
cc: warning: argument unused during compilation: '-L/usr/local/lib' [-Wunused-command-line-argument]
qmail-remote.c:176:7: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
  get(&ch); code = ch - '0';
      ^~~
qmail-remote.c:177:7: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
  get(&ch); code = code * 10 + (ch - '0');
      ^~~
qmail-remote.c:178:7: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
  get(&ch); code = code * 10 + (ch - '0');
      ^~~
qmail-remote.c:180:9: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
    get(&ch);
        ^~~
qmail-remote.c:182:28: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
    while (ch != '\n') get(&ch);
                           ^~~
qmail-remote.c:183:9: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
    get(&ch);
        ^~~
qmail-remote.c:184:9: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
    get(&ch);
        ^~~
qmail-remote.c:185:9: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
    get(&ch);
        ^~~
qmail-remote.c:187:26: warning: passing 'unsigned char *' to parameter of type 'char *' converts between
      pointers to integer types with different sign [-Wpointer-sign]
  while (ch != '\n') get(&ch);
                         ^~~
qmail-remote.c:270:3: error: use of undeclared identifier 'OSSL_HANDSHAKE_STATE'
  OSSL_HANDSHAKE_STATE state = ssl ? SSL_get_state(ssl) : TLS_ST_BEFORE;
  ^
qmail-remote.c:271:7: error: use of undeclared identifier 'state'; did you mean 'stat'?
  if (state & TLS_ST_OK || (!smtps && state & TLS_ST_BEFORE))
      ^~~~~
      stat
/usr/include/sys/stat.h:348:5: note: 'stat' declared here
int     stat(const char * __restrict, struct stat * __restrict);
        ^
qmail-remote.c:271:15: error: use of undeclared identifier 'TLS_ST_OK'
  if (state & TLS_ST_OK || (!smtps && state & TLS_ST_BEFORE))
              ^
qmail-remote.c:271:39: error: use of undeclared identifier 'state'; did you mean 'stat'?
  if (state & TLS_ST_OK || (!smtps && state & TLS_ST_BEFORE))
                                      ^~~~~
                                      stat
/usr/include/sys/stat.h:348:5: note: 'stat' declared here
int     stat(const char * __restrict, struct stat * __restrict);
        ^
qmail-remote.c:271:47: error: use of undeclared identifier 'TLS_ST_BEFORE'
  if (state & TLS_ST_OK || (!smtps && state & TLS_ST_BEFORE))
                                              ^
qmail-remote.c:430:3: warning: implicit declaration of function 'SSL_CTX_set_post_handshake_auth' is invalid
      in C99 [-Wimplicit-function-declaration]
  SSL_CTX_set_post_handshake_auth(ctx, 1);