Postfix and OpenJDK 11: “No appropriate protocol (protocol is disabled or cipher suites are inappropriate)”

I was facing the same issue using JDK 11. But I resolved it by commenting this line in the java.security file:

jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA,
    DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL,
    include jdk.disabled.namedCurves