Yes, if for some reason you need to deactivate your account, log into your account and choose Salesforce in the left menu.
From there, you can turn the “sync emails” switch off. This means that we will immediately stop syncing. Once you are ready to reactivate, you can do that here in just a simple click.
If instead, you want to delete your account completely, you can do so in Settings.
If you want to delete your account because things are unclear, please mention the problem you are experiencing. We might just have a simple solution for it...