Please do not add duplicate addresses to POIs: "Usually address informations doesn't need to be duplicated; i.e., there should be only one addr:housenumber=* per street and house number (which would typically be placed on the building). Software can usually link addresses to other features by geographical proximity, and duplicated addresses are often flagged as errors by quality assurance tools." - https://wiki.openstreetmap.org/wiki/Addresses#How_to_map

If you absolutely want to add a contact address use tags with the prefix contact rather than addr for this. A detailed description can be found here: https://wiki.openstreetmap.org/wiki/Key:contact:*#Mail_address