I configured Thunderbird to alert me to all incoming emails by showing a preview window (no sound), which I can then very quickly scan to see if the email is im

I configured Thunderbird to alert me to all incoming emails by showing a preview window (no sound), which I can then very quickly scan to see if the email is important (I had several near miss emails from my university, but, as a student, I can't tell them not not send me urgent email).