Ebean database model with a serialized object column

I am using playframework with ebean. I have the following model:

public class MailData {
  private String title;
  private String body;
}

public class Envelope extends Model {
  @Id
  private UUID id;

  private MailData mailData;
  private Date sent;
}

I want to have one database table, the envelope. This table should have a column MailData in which a serialized string of the MailData object will be stored. How can I do this?

The closest I have come is with the @Embeddable and @Embedded tags which results in the fields title and body being inside the envelope table which is not the desired outcome.

I have found a way to do it using a Converter:

@Converter
public class MailDataConverter implements AttributeConverter<MailData, String> {
  @Override
  public String convertToDatabaseColumn(MailData attribute) {
    //serialize here
  }

  @Override
  public MailData convertToEntityAttribute(String dbData) {
    //deserialize here
  }
}

public class MailData {
  private String title;
  private String body;
}

public class Envelope extends Model {
  @Id
  private UUID id;

  @Column
  @Convert(converter = MailDataConverter.class)    
  private MailData mailData;

  private Date sent;
}