How to add signatures:

1. Create your signature first.

Step 1. Click the button "Edit Signature" as shown bellow, then the signature edit dialog appears.

Step 2. Enter the signature name, draw your signature, and click "OK" button to save it.

2. Select your singatures and add it to current email.

Step 1. Select "Signatures" in resource type.

Step 2. Select your signatures and preview it.

Step 3.Add the signature to email at current cursor.

The result is shown bellow: