import  javax.activation.DataSource;

 public   class  AttachmentDataSource  implements  DataSource {
    
     private  Attachment attachment;
    
     public  AttachmentDataSource(Attachment attachment) {
         this .attachment = attachment;
    }
    
     public  String getName() {
         return  attachment.getFileName();
    }
    
     public  String getContentType() {
         return  attachment.getContentType();
    }
    
     public  OutputStream getOutputStream() {
         return   null ;
    }

     public  InputStream getInputStream() {
         return   new  ByteArrayInputStream(attachment.getData());
    }

     public  Attachment getAttachment() {
         return  attachment;
    }

     public   void  setAttachment(Attachment val) {
         this .attachment = val;
    }

}

...
Message msg =  new  MimeMessage(mailSession);
            
            msg.setFrom( new  InternetAddress(eMail.getFromAddress()));
            msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(executedService.getSubscribedservice().getAddress().getEmail()));
            msg.setSubject(eMail.getSubject());
            msg.setSentDate( new  Date());
            
            MimeBodyPart bodyPart =  new  MimeBodyPart();
            bodyPart.setText(eMail.getBody());
            
            Multipart multiPart =  new  MimeMultipart();
            multiPart.addBodyPart(bodyPart);
            
             if  (eMail.getAttachments() !=  null ) {
             
                Attachment[] attachments = eMail.getAttachments().toArray( new  Attachment[ 0 ]);
                
                 for  ( int  i =  0 ; i < attachments.length; i++) {
                    AttachmentDataSource ads =  new  AttachmentDataSource(attachments[i]);
                    MimeBodyPart attachmentPart =  new  MimeBodyPart();
                    attachmentPart.setDataHandler( new  DataHandler(ads));
                    attachmentPart.setFileName(ads.getName());
                    multiPart.addBodyPart(attachmentPart);
                }
                
            }
...