Exception in thread "Thread-20" java.lang.ArrayStoreException

Olá galera, boa tarde.
Estou tendo o seguinte problema ao tentar enviar email pela minha aplicação:
[color=red]Exception in thread "Thread-20" java.lang.ArrayStoreException
at java.lang.System.arraycopy(Native Method)
at java.util.ArrayList.toArray(Unknown Source)
at org.apache.commons.mail.Email.toInternetAddressArray(Email.java:1268)
at org.apache.commons.mail.Email.buildMimeMessage(Email.java:1069)
at org.apache.commons.mail.MultiPartEmail.buildMimeMessage(MultiPartEmail.java:254)
at org.apache.commons.mail.HtmlEmail.buildMimeMessage(HtmlEmail.java:514)
at org.apache.commons.mail.Email.send(Email.java:1162)
at xpro.xmanager.xutil.mail.SendMail.run(SendMail.java:83)
[/color]

Minha classe de configuracao do email é esta (SendMail.java):

private HtmlEmail emailConfig() throws EmailException {
		EmailConfig cfg = new EmailConfig();
		HtmlEmail email = new HtmlEmail();
		Set<String> copias = new HashSet<String>();
		email.setDebug(true);
		email.setHostName(cfg.getHostName());
		email.setFrom(cfg.getFrom(), cfg.getTitle());
		email.setCharset(cfg.getCharset());
		email.setAuthentication(cfg.getAuthentication(), cfg.getPassword());
		email.setSmtpPort(Integer.parseInt(cfg.getSMTPPort()));
		email.setSslSmtpPort(cfg.getSMTPPort());
		for(String copiasEmail : cfg.getCopiasEmail().split(",")) {
			copias.add(copiasEmail);
		}
		email.setCc(copias);
		return email;
	}

       @Override
	public void run() {
		try {
			email.send();
		} catch (EmailException e) {
			throw new RuntimeException(e);
		}
	}

desde já agradeço.