As you must have noticed there is no option to Sign Out of the Mail App on iPhone. However, you can still Log Out of Email on iPhone using steps as provided below.
Log Out of Email on iPhone
The iPhone Mail App allows you to access all your Email Accounts within the App, without the need to login to your individual Email Accounts.
Once Email Accounts are added to iPhone, the Mail App gets synced with your Email Accounts and it keeps bringing new messages to iPhone from your Email Accounts.
As mentioned above, there is no Sign-out option in the Mail App and the only way to Log out of Email on iPhone is by using steps as provided below.
Step#1 – Switch OFF Mail
The first step is to switch OFF the option to receive Mail in your Email Account, within the Mail App.
1. Go to Settings > Mail > Accounts > tap on your Email Account (in this case it is Gmail).
2. On the next screen, move the toggle next to Mail to OFF position.
After this, you will no longer find messages from your Email Account appearing in Inbox of the Mail App.
However, your Email Account will still remain linked to the Mail App, which allows you to re-enable the Email Account in Mail App at any time and start receiving messages from your Email Account.
Note: If you are switching to dedicated Gmail or Outlook App, you will have to remove your Email Account from the Mail App by tapping on Delete Account option.
Step#2 – Switch OFF iCloud Mail
Even after the Email Account is switched OFF, you will still find messages from your Email Account syncing to iPhone via iCloud.
If you do not want to see your Email Messages in the Mail App, you will have to turn OFF iCloud Access for the Mail App on your iPhone.
1. Open Settings and tap on your Apple ID Name.
2. On Apple ID screen, tap on iCloud.
3. On the next screen, move the toggle next to Mail to OFF position.
After this, the Mail App won’t be able to access iCloud and you will no longer find your Emails appearing in the Mail App via iCloud.