protected override void Initialize()
{
if (StringUtils.IsNullOrEmpty(ToList) && StringUtils.IsNullOrEmpty(CcList) && StringUtils.IsNullOrEmpty(BccList)) {
throw new BuildException("There must be at least one name in"
+ " the \"tolist\", \"cclist\" or \"bcclist\" attributes"
+ " of the <mail> task.", Location);
}
}