Revert "Indicate the user with a red color when an invalid email id is entered"

This reverts commit 0bf8b21ce9e9018ff6f7ae5c1e6f8bbd12c86a77.
Indicate the user with a red color when an invalid email id is entered

When the user enters an invalid email ID in the input area for
recipient, the user is indicated with red background color in the input
space.