I have thunderbird installed on my Windows 8.1 PC at work and I also check my emails using a MAC laptop, my iPhone and iPad using their standard apple email software and lately some of my emails, not all are not showing up on my inbox in Thunderbird (Windows PC) though they show on my apple devices with no problems. However if I search for these emails, they come up. It's randomly doing this and I believe it's mostly with emails that I am replying from my apple devices though I am not sure. I checked all my settings on every device and they all appear fine. The email is set up on all devices as IMAP and when I logged in to the actual email server, it does show that the email is in the inbox as well but it's not showing up on Thunderbird. I tried everything. Can someone please tell me how to fix this and what I missed?