Open your HTML email signature file in your web browser.
Press Ctrl + A (Cmd + V for Mac) to select the entire email signature, then press Ctrl + C (Cmd + C for Mac) to copy it.
IMPORTANT: Do not use your mouse to select the area, only use Ctrl + A as you may miss out on grabbing some of the code.
Open eM Client and click the hamburger icon (three horizontal lines) at the top left of your screen. Select Settings.
On the left menu, expand Mail and select Templates and Signatures. Click the Signatures... button.
Create a New signature by clicking the button at the top left of the window. Enter a name for your email signature, then paste your email signature in the field below by clicking inside and pressing Ctrl + V to paste your copied signature. Click Save.
Close out of your settings and compose a new email. Your email signature will now automatically insert when sending an email within eM Client.