What is the meaning of i circled symbol in sent mail folder

[watercrazed]

Sometimes when I send an email there is a i circled symbol lower right
corner of envolpe symbol in the sent messages folder, it is kind of like the
blue arrow when you forward a email. What does the i circled indicate?

 

[Sue Mosher [MVP-Outlook]]

It means that tracking information is available for that item. You'll need
to open the item to view the Tracking tab.