Hello, I'm new here. For years I've had a simple HTML/PHP email contact form on my website, which if properly completed sends me the visitor's message with their email in the Reply-To field so I can easily respond. This month Thunderbird's handling of these messages changed. It correctly shows the Reply-To address in the message pane, but clicking Reply gives a compose-new-message window with the To address (i.e. mine) copied from the original message and Reply-To set to the visitor's email.
On further investigation it seems that this happens only when the From address of the message sent by the script is recognized by Thunderbird as one of my "identities". If I substitute an "unknown" address, Reply now correctly replies to the visitor's email.
Is this the intended behaviour?
