When I email someone, they see that the email is from me. If they hit 'Reply', my email address disappears from their 'To' box, and it is replaced by a Yahoo email address. When they send their reply, it bounces back.
I looked at the email I sent, and selected 'View source'. There, I can see the that the 'From' is my email address but 'Reply-To' is set to this mystery address.
Do you think I've been hacked or is there a setting that I need to change somewhere? I'd be very grateful for your ideas! Many thanks.
