Unsubscribe header iOS

Hello,

We have implemented in ACC V7 the unsubscribe header as per https://experienceleaguecommunities.adobe.com/t5/adobe-campaign-classic-questions/unsubscribe-header/m-p/383432#M3440
"Precedence: bulk
List-Unsubscribe: <mailto:<%= provider.errorAddress !='' ? provider.errorAddress:delivery.mailParameters.errorAddress %>?subject=unsubscribe<%=escape(message.mimeMessageId) %>>"

This seems to work for gmail, but not for iOS email clients.
Anything missing on this to work also for iOS?

Thank you!