If there isn’t an existing signature, click “New” and create one.In the top-right corner of the signatures box, you will be able to select default signatures and whether to include signatures automatically on replies.Once you are done, click “OK” and your changes will be saved.
Click “File“, then click “Options” in the left-hand menu.
Select “Mail” from the list of options, then click “Signatures“.
Replace the existing signature with your desired new one.
If you use the “Send mail as” feature to send from different addresses in your account, you can add a different signature for each address.
To select an address, use the drop-down menu above the signature text box on the Settings page.
If you don’t see the drop-down menu: in your signature after you send messages, it's because some versions of Gmail don't support features like bolding or italics.
For example, text you bolded in your signature might be marked with asterisks, so example would show as *example*.
Most of the time, you can only use 10,000 characters in your signature.
Sometimes, it’s the little things that can give us the most annoyances.
As often as software gets updated, things that used to be common knowledge now have entirely new ways of getting done, and the way it used to be doesn’t apply.
Something as necessary as changing your email signature, for example, gets lost in the shuffle of new menus and options.