Your main Yahoo Mail account uses your Yahoo ID in your email address ([email protected]). To protect your Yahoo ID while sending and receiving email messages, you can use a Yahoo email alias instead of your main Yahoo email address.
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A Yahoo email alias is simply another Yahoo email address that you can use as a disguise for your main Yahoo Mail account that contains your Yahoo ID.
Instead of providing your [email protected] address to receive messages or using it in the From: field when sending messages, you can use your own [email protected] address instead.
Any messages sent to your Yahoo email alias will automatically be received in your main Yahoo Mail account. Similarly, any messages you want to send from your Yahoo Mail email alias can be sent from your main Yahoo Mail account.