Bittrex sends withdraw emails promptly when you press the withdraw button. If you do not receive the withdraw email you should make sure you check your spam folder and also whitelist bittrex.com at your email provider.
You can always cancel a withdraw and try again, this will send you a new email.
If you are still unable to receive email you may need to change the email on file with Bittrex.
You could also enable 2fa which does not require email authentication.
In order to change your email on file with us please provide some of the following.
- Past Deposits
- Recent Orders
- Approximate Balances
The more you can provide the easier it will be to verify your account and change your email address. Accounts with high balances will require more information for verification.