In order to insert image to mail merge campaign, template or SalesHandy profile, you need to have a direct link to an image which can be inserted in the text editor.
If you don't have the image link to the file, then you can get it from Postimg (http://postimages.org/)
Step 1: Upload the image to postimg.org (Click the image to zoom.)
Step 2: Copy the direct link.
Step 3: After having direct link, go to SalesHandy webapp. In that, mail merge campaign, email template or email body wherever you wish to upload image.
Step 4: Now, click on insert image.
Step 5: Insert your direct link in "Source" option.
And your image is uploaded. Same steps are use to upload image anywhere in SalesHandy. Need to know more, reach us at firstname.lastname@example.org.