Update _index.md

Fixed typo

Author: robertpatrick

documentation/3.0/content/release-notes/_index.md

@@ -23,7 +23,7 @@ None
 - #1412: Fixed a bug in the Prepare Model integration with WKTUI.
 - #1413: Fixed a number of internationalization message-related issues.
 - #1414: Fixed a bug with wallet collection during discovery of a Proxy data source.
-- #1416: Fixed a bug in the handling of main session properties with credentials that was causing a Jython AttributeError (Issue #1415).
+- #1416: Fixed a bug in the handling of mail session properties with credentials that was causing a Jython AttributeError (Issue #1415).
 - #1419: Fixed open issue from previous releases regarding wlst attribute not defined errors in online remote discovery. 
 - #1420: Fixed a bug where a trailing slash on an application `SourcePath` would cause a empty ZIP file error.