With Outlook, you can reduce the chance of this happening to you.
Get Reminded to Reply to a Message in Outlook
To make Outlook reminded you to reply to an email:
- Right-clicking on the message you want to set the reminder for.
- Select Follow Up | Add Reminder... from the menu.
- In Outlook 2000-2003, select Flag for Follow Up from the context menu.
- Choose the date when you have to completed the task.
- Click OK.
Unfortunately, this only works so long as the message is in your Inbox. To enable reminders for messages in other folders, you can use Extended Reminders.