Gmail now allows you to use multiple signatures. Multiple signatures give you the flexibility to use different signatures for different situations. With multiple signatures, you can swap out your signature while you compose an email by clicking the Insert signature button at the bottom of the window. You can also set different default signatures for new emails and emails that you reply to in the signature settings.

To create multiple signatures:

1. In Gmail, click the Gear icon and then See all settings.
2. From the General tab, scroll down to the signature section.
3. Click the Create New button and enter a name for the new signature.
4. Select the name of your new signature and fill in the text box to the right of it with your signature details.

Learn more about creating a signature in Gmail at https://support.google.com/a/users/answer/9259758#4.1