pop3接收邮件问题 ( 积分: 100 )

var i : integer;
packname : string;
begin
for i := 1 to POP3.MailCount do
begin
POP3.GetSummary(i);
label8.Caption:=Trim(POP3.Summary.Subject);
if Trim(POP3.Summary.Subject) = '@@至通数据传输@@' then
begin
POP3.GetMailMessage(i);
packname :=Trim(POP3.MailMessage.Attachments.Strings[0]);
if copy(packname,7,4)<> trim(label5.Caption)then
begin
SysUtils.DeleteFile(in_path + '/' + packname);
Continue;
end
else
begin
POP3.DeleteMailMessage(i);
end;
end;
end;
end;

报错 list index out of bound(0)
Trim(POP3.MailMessage.Attachments.Strings[0]);
是这句出问题 么解决 请大虾帮我一下呀