Off topic question re Mail

Guys

When I reply to a mail, Mail shows an arrow on the viewer page.

In the past, I could click on the arrow in the inbox viewer page and that would call up the reply I had sent. Thus there was no need for me to go searching in the Sent box.

For some reason this arrow no longer works, whether I have opted for related messages on not.

Is this a problem with my system - Lion - or is it a bug?


T