Hello! My name is*****
It looks like the cause of the problem is with the phone. First, make sure that your e-mail account on your LG G4 phone was really configured as IMAP. Then, make some changes on the phone, for example, delete one of the e-mails in the Inbox folder. After that, tap on the refresh icon that is used to manually check for new e-mails. That should synchronize the changes with your e-mail account.
Check with Outlook to see if the e-mail you deleted is still there. You can press the F9 key in Outlook to synchronize the changes.
Let me know the results.
Have you tried what I suggested - delete one e-mail in the Inbox folder and tap on the refresh icon, and then check with Outlook?
Are you using the default Android mail app that came with the phone, or you installed another one?
Please remove the e-mail account from the phone, and then restart the phone. After the restart, set up the account again and check the results.
Has there been any changes when you removed and re-added the same e-mail account on your LG G4 phone?
Let me know,
I could be a problem with the mail app. If you have another e-mail account, please add it on your phone and check if it will synchronize correctly when you make changes.
In that case, it seems that the default mail app is not working correctly. You can install another mail app and add your e-mail accounts there.
Here are 3 good mail apps. You can find them on Google Play or on these links:
1. TypeApp Mail:
2. Aqua Mail:
3. CloudMagic Email
Hopefully, one of them will work correctly for you.