We have a multisite installation where we run a number of sites. Some of these sites has multiple domains. This is not domains sharing a domain base, but quite different domain names (mydomain.no and yourdomain.org). These have been implemented using Apache ServerAlias and works fine. The problem comes when a user want to log in. The original domain works, but the new ones are not working (returning to starting page upon log in). We have tried the recipe given in https://www.drupal.org/node/1348784, but this does not seem to work with Drupal 7 (7.44, soon to be upgraded). It also says in the text that this only works for the default sites folder. Is there a way to make this work with multisite installation?