What is a signature, and how do I change it?A signature is a personalized text file or "footer" attached to the end of an outgoing email message. Yahoo! Mail's Signature feature allows you to add personal contact information, a quote or favorite saying, or anything you like to the end of each of your outgoing email messages.
When using Yahoo! Mail, you always have the option to add or remove your signature before sending a new message by clicking the "Use Signature" checkbox on the Compose Mail screen.
To view or change your signature:
Click the "Options" link in the left-hand navigation bar, and then click the "Signature" link under the Personalization column on the left.
Your current signature (if any) will be displayed in the text area.
Change your signature by typing over the existing text, or enter a new one by typing in the blank text area. If you're using HTML tags, click the "HTML" button. (Note: When using HTML in your signature, make sure you click the "HTML tags allowed" button in the Compose field. If you don't do this, the recipient will only see what is written in plain text.)
If you would like the "Use Signature" checkbox on the Compose Mail screen to be checked by default when composing a new message, click on the "Add signature to all messages as default" checkbox beneath the text area. (You will still have the option to uncheck this box if you want to send a message without your signature.)
Remember to click the "Save" button when you're done. This will put your new signature into effect.