Yes! This is a feature of the Mirosign team plan.
As long you have added a promo banner image to the email signature generator and your staff have already installed this email signature, you can automatically update this promo banner image.
Note: you must upload the same file type for this to work, such as: .png, .jpg, .jpeg, .gif.
335 pixels wide by 100 pixels high
I don’t have a promo banner image now, but I want one in the future
If you want staff to install the email signature now, but plan to add a promo banner in the future, we recommend uploading a blank, white promo banner image 335 pixels wide by 100 pixels high now with a view to changing this image in the future, which will automatically update as long as you use the same file type. This will avoid staff members having to reinstall at a later date.
The promo banner URL link
Unfortunately the URL banner link is not changeable, this is locked in when staff members install the email signature. If this changes on your signature generator, then staff will have to reinstall.