MAIL发送报'InComplete Header'出错信息，请指点！(100分)

本人写了一小程序进行邮件群发，结果在
　　ry
NMSMTP1.SendMail;
except
时报报'InComplete Header'出错信息，请大侠指教！
主体程序如下
NMSMTP1.Host:=Edit5.Text;
NMSMTP1.UserID:= Edit6.Text ;

NMSMTP1.PostMessage.FromName := FName;
NMSMTP1.PostMessage.Subject := FSub;
NMSMTP1.PostMessage.ToAddress.Clear;
NMSMTP1.PostMessage.ToAddress.Add(StrMail);
NMSMTP1.PostMessage.Body.Add(FBodyContent);
try
try
NMSMTP1.SendMail;
except
ShowMessage('邮件服务器连接出错！');
end;