Maybe if you share what these random notifications are, plus the domains of the three email accounts, someone may figure out whatever is your problem. Thank you.

Maybe if you share what these random notifications are, plus the domains of the three email accounts, someone may figure out whatever is your problem. Thank you.

Sorry, I was in a rush and I was not obvious enough. I don't know what are the notifications. A red number appears in the icon (Like when I got a new mail), but when I open the application, no new email, everything is read. The sounds is played, but notification is not shown. (I have thunderbird's notification, not the system's) It stay there until I change the email folder. When I actually getting an email, it's working fine, as expected. All three email is though google. (One @gmail.com, 2 custom domain but both though google) I checked windows notifications too, but nothing is there. Something I'm getting a notification like every 30 minutes.