Relevant Products: Exclaimer Cloud - Signatures for Office 365 | Exclaimer Cloud - Signatures for G Suite
Scenario
You have inserted the {Mobile} and {Telephone} fields into your signature design. When your signature gets appended to an email, a blank space is displayed as you do not have a mobile number specified.
How will you ensure that if the data for any fields is not available then the fields get hidden? 
Resolution
Signatures are designed using fields to populate user details from synchronized data. By default, a signature field is automatically hidden if no data is found to populate it.
If a signature is applied to a user for whom no mobile or telephone is present, the entire field (including its m: label) also gets hidden. This ensures that the signature always looks neat and professional, with no odd spacing or gaps.
Check for yourself
Within the Visibility settings, make sure the Hidden if this field is empty option is selected.
The default behaviour for all fields is Hidden if this field is empty, so you never need to worry about missing data. However, if required, you can choose an alternative setting here (for the associated field).