I posted something on this a few years back. I had my Bell Mail synched with Gmail and when I received a new email it was read by both servers. I deleted it from Bell after reading it. Then because Gmail also received it Gmail sent it to Bell not rec...
I had a similar problem long ago and had a debate with Bell support online about it. I deleted an email and it (several actually) was received again. Bell said "impossible". Months later I found the problem. I had synched (actually OVER synched) my G...