Though a lost Gmail account can be recovered by multiple ways but recovery using mobile SMS/phone call is the simplest way. All you need is to provide the verification code sent to the mobile number you entered while registering for the Gmail account.
Gmail account recovery using mobile SMS
1. First click ‘Can’t access your account’ link in the login box.
2. Next click ‘I forget my password’. Enter email address. Enter captcha when asked.
3. Ask for verification code through SMS or phone call. We asked for the mobile SMS.
4. Enter the verification code.
5. Now enter your new password.
6. Your Gmail account is successfully recovered.
Now you can login on Gmail (or any Google service) using the new password.