If you are using a central e-mail signature then you will need to disable your signature in the iOS so a duplicate isn’t added (or the central signature is ignored). You won’t see the central signature on your e-mail, it is added when it is sent. (You will see the signature on replies you receive).
- Open Settings on your Home screen.
- Scroll down and tap Apps.
- Scroll down and tap Mail.
- Select Signature.
- If you have multiple accounts, choose the one you want or select All Accounts.
- Tap the existing signature text and delete it until the field is blank.
- Tap < Mail (or Back) to save and exit.
- Open the Mail app, start a new email, and confirm the signature is gone.