question

sensing email replay ?

I can not get the mean?

you lost the email or else?

Tools > Options > Preferences tab >

Email Options > Advanced Email Options >

Choose your preferences for alerts in the
"When new items arrive in my inbox" section.

When you are done, click OK at the bottom of each dialog box to close it.

-- If this is what you are asking for, I'm not surprised that you could not find it. It is quite well hidden. :)