src/main/jdk1.9/module-info.java:9: error: module not found: mail
    requires static mail;
                    ^
src/main/jdk1.9/module-info.java:10: error: module not found: java.mail
    requires static java.mail;
                        ^
src/main/jdk1.9/module-info.java:11: error: module not found: activation
    requires static activation;
                    ^
src/main/jdk1.9/module-info.java:12: error: module not found: java.activation
    requires static java.activation;
                        ^
4 errors
Caused by https://github.com/bcgit/bc-java/commit/0fe6009

--- a/src/main/jdk1.9/module-info.java
+++ b/src/main/jdk1.9/module-info.java
@@ -5,12 +5,6 @@ module org.bouncycastle.mail
     requires java.datatransfer;
     requires org.bouncycastle.util;
 
-    // optional: javax.mail/javax.activation go by these four names depending on the artifact used, a hard requires on any one of them breaks the rest.
-    requires static mail;
-    requires static java.mail;
-    requires static activation;
-    requires static java.activation;
-
     exports org.bouncycastle.mail.smime;
     exports org.bouncycastle.mail.smime.handlers;
     exports org.bouncycastle.mail.smime.util;