Yahoo! highly recommends to also use one-click unsubscribe - https://senders.yahooinc.com/subhub/ .
Is it possible to also implement it in Acymailing? (it takes one more line in the header, i.e. „List-Unsubscribe-Post: List-Unsubscribe=One-Click”)
„Supporting One-Click Unsubscribe
We highly recommend setting up one-click unsubscribe. To do this you need include the following code within the headers of your email:
Once a user unsubscribes, you will get a POST request which looks like this:
POST /unsubscribe/opaquepart HTTP/1.1
Of course we support “mailto:” unsubscribe headers as well.”