You are using Exclaimer Cloud and creating your signature template. You have to select the font size within your signature template.
You set a font value of 12, which you believe to be in points (pt). But, when you test and review the email, it is showing much smaller.
Most mail clients render fonts at point sizes (pt). For more information, please see Pixel to Point conversions table.
- Set the value exactly as required and verify that it is set to px (pixel) instead of pt (point).
- You can set the Font value in pt or px and swap between the two within the Font Size drop-down list. By default, any value set in pt will be converted to px.
You can change px or pt from here: