I think I've found root cause, and it strikes me as a bug. DEFAULT_EMAIL_PATTERN in DefaultReportJobValidator.java wrongly excludes lots of characters that are valid email address characters. public static final String DEFAULT_EMAIL_PATTERN = "^[^\\~\\`\\(\\)\\[\\]\\{\\}\\:\"\\;\'/\\?\\<\\>\\+\\=\\\\|\\!\\@\\#\\$\\%\\^\\&\\*]+@([\\w+\\-]+\\.)+(\\w+)"; Of course, the authority on this matter is likely one or more RFCs, which I must dig up, but here's a summary from Wikipedia: http://en.wikipedia.org/wiki/E-mail_address#Local_part Looks like I need to patch the source and do a custom build. And perhaps file a bug? Dane