Open Gmail in a web browser
Sign in to your account
Click the checkbox at the top left to select all visible emails
Click the “Select all conversations in Inbox” link if it appears
Click the trash icon to move the selected emails to Trash
Repeat the selection and deletion in other folders or tabs such as Promotions, Social, Updates, Sent, and Drafts
To delete all mail in Gmail, go to the search bar and enter `in:anywhere`
Press Enter to show all mail, including archived messages
Click the top-left checkbox to select all visible emails
Click the “Select all conversations that match this search” link if it appears
Click the trash icon
Go to the Trash folder
Click “Empty Trash now” to permanently delete the mail
If needed, repeat the process for Spam and then empty Spam
On mobile, use the Gmail app to select emails in each folder and delete them
Use Gmail filters and search terms to target specific mail if you do not want to delete everything