Error sending Mail on Payara with Jenkins

[Andreas]

Hi,

since a short time i got this error sending mails:

  30-Jan. 16:43:50 WARN  (EmailSender.java:run:52) Problem Sending email (subject: Email From Tachyon Online) to info@tachyon-online.de
com.konakart.app.KKException: Error sending email: class io.jenkins.plugins.javax.activation.DelegatingCommandMap cannot be cast to class javax.activation.MailcapCommandMap (io.jenkins.plugins.javax.activation.DelegatingCommandMap is in unnamed module of loader jenkins.util.AntClassLoader @502ebe1a; javax.activation.MailcapCommandMap is in unnamed module of loader org.apache.felix.framework.BundleWiringImpl$BundleClassLoader @40fa700)
        at com.konakart.bl.Emailer.send(Emailer.java:998)
        at com.konakart.bl.EmailSender.run(EmailSender.java:49)
        at java.base/java.lang.Thread.run(Thread.java:829)

If i undeploy Jenkins 2.332 on Payara 5.2021.10 this error don't appear.

Anybody also this strange issue.

Thx
Andreas