I have the same problem. strace reports a problem with a library: [pid 30353] writev(2, [{"smtpd", 5}, {": ", 2}, {"relocation error", 16}, {": ", 2}, {"/usr/lib/libpostfix-tls.so.1", 28}, {": ", 2}, {"symbol SSL_CTX_sess_set_get_cb, "..., 114}, {"", 0}, {"", 0}, {"\n", 1}], 10) = 170
regards, Jörg