We used to have access to custom values to call action to get an image into the email builder. But for reasons that i cant understand we dont have access to this feature, receiving the answer that it's not available and suggesting me this way to get back. If we thing out of the box, if we are going to install a snapshot, with all email marketing included, adding the logo and some images like the signature logo, this is the best way, with a custom value. Keep in mind the precious time consumed changing every single 'cause we dont have this feature available, when ( as i told before) we used this feature before. I hope that people vote for this feature and make this happens.