Apple

Saw this in Sequoia, and it looks like my fix was removed when upgrading to Tahoe.

Was seeing a strange issue w/ macOS mail. Didn't see it in iOS or iPadOS, just on the desktop client. I receive hotel receipts from travel to, e.g., a Hotmail address, and mobile phone receipts to a Gmail address. They both need to be forwarded to a work address. If I forward on from the Hotmail address, when I later try to forward my mobile receipt, after entering the work email address in the "To" line, the "From" lline will automatically change to my Hotmail address. When the forward window initially comes up, it shows my Gmail address, because that's the account that received the original email, but once I plugged in the "To" address, it changes the "From" address to the last email account that sent a message to that "To" address.

Maybe I'm alone here, but I think this is bizarre behavior! To fix it, go to Settings (⌘-,) --> Composing. Under Addressing, change "Send new messages" from "Automatically Select Best Account" to a specific email address. This will make forwards behave as expected w/o changing the From address, but all new emails will default to being from your new default "From" address.