It won't be Chrome that is blocking gmail. Gmail will have been blocked in your blocked senders list. You can check by logging onto your email account and clicking on your username at the top right then go to "Mail" then 2Blocked Senders". Scroll down until you fine the gmail domain. Tick the box beside it and click "Delete".
If however you want to remove Chrome, assuming you are using a Windows computer you will need to go to Settings then "Apps" and scroll down till you find Chrome then click on it then click "uninstall.
