Maven library fails with java.lang.VerifyError: Verifier rejected class ... on Android 11

[M66B]

Describe the bug

Library version 1.6.5 from:
https://mvnrepository.com/artifact/com.sun.mail/android-mail
https://mvnrepository.com/artifact/com.sun.mail/android-activation

Caused by: java.lang.VerifyError: Verifier rejected class com.sun.mail.handlers.handler_base: java.awt.datatransfer.DataFlavor[] com.sun.mail.handlers.handler_base.getTransferDataFlavors() failed to verify: java.awt.datatransfer.DataFlavor[] com.sun.mail.handlers.handler_base.getTransferDataFlavors(): [0x4]  can't resolve returned type 'Unresolved Reference: java.awt.datatransfer.DataFlavor[]' or 'Reference: javax.activation.ActivationDataFlavor[]' (declaration of 'com.sun.mail.handlers.handler_base' appears in /data/app/.../base.apk)
        at java.lang.Class.newInstance(Class.java:-2)
        at javax.activation.MailcapCommandMap.getDataContentHandler(MailcapCommandMap.java:601)
        at javax.activation.MailcapCommandMap.createDataContentHandler(MailcapCommandMap.java:573)
        at javax.activation.CommandMap.createDataContentHandler(CommandMap.java:205)
        at javax.activation.DataHandler.getDataContentHandler(DataHandler.java:594)
        at javax.activation.DataHandler.getContent(DataHandler.java:521)
        at javax.mail.internet.MimeMessage.getContent(MimeMessage.java:1475)

Smartphone:

• Device: Pixel 3a XL
• OS: Android 11 beta 1

Additional context
The same library works without problems on Android 10.

Compiling the source inline with the app solves the issue on Android 11:
M66B/FairEmail@286a8fd

My guess there is something wrong with the build process / published library.

[rivercartwright]

The same problem exists on the released version of Android 11.

[rivercartwright]

I have a convoluted workaround for this problem. It's temporary.

I switched to using the release candidates of the Eclipse Jakarta Mail and Activation components.

    implementation 'com.sun.mail:jakarta.mail:2.0.0-RC6'
    implementation 'com.sun.activation:jakarta.activation:2.0.0-RC3'

However, there is a bug in the pom.xml metadata of the activation library that prevents Android from compiling it.
jakartaee/jaf-api#53

While I wait for a fix to be incorporated and published I was able to unjar the activation jar, fix the pom.xml, jar it up again and then use it directly.

    implementation('com.sun.mail:jakarta.mail:2.0.0-RC6') {
        // This exclusion and the inclusion of the modified jar below are to work around
        // an error in the pom.xml metadata. https://github.com/eclipse-ee4j/jaf/issues/53
        exclude group: 'com.sun.activation', module: 'jakarta.activation'
    }
    implementation files('libs/jakarta.activation-2.0.0-RC3-mymod1.jar')

[lukasj]

same as #489, closing in favor of that one (has more comments...)