I have just discovered how to turn off the annoying threading of emails received in Gmail when subject lines or email address from fields are the same or similar.
Believe me I am over the moon.
1. In Gmail, go to ‘Settings’.
2. Click on Conversation view off option.
3. Save setting..
Now I know this and have shared it. I do hope that anyone who has spent months trying to work it out and has found this, will be feeling a lot better. I know I am! Pesky thing been bothering me for months!