American Express USA profile stores Home, Business and an Alternate address. One of these can be designated as the Mailing address. All of this can be viewed and edited online:
https://global.americanexpress.com/a...gement#profile The only time it seems to be necessary to call is if you need more than one Mailing address, but perhaps there are other circumstances that do not permit self service changes.
You CAN NOT change or ADD any alternative address online. If so, I would have done that and steered clear of calling them. I travel so I want ALL correspondence going to just one address/box that is secured.