Share Page By Email shows 127.0.0.1 instead of Domain or Wiki name

If i use "Send Page By Email" to notify somebody. The text shows 127.0.0.1 insted domain or wiki name.

** [...]thought you might be interested in the document Home on 127.0.0.1.

The link himself is correct, with domainname and brings you to the right page if you click on it.

Alias under /xwiki/bin/view/XWiki/XWikiServerXwiki is set to https://wiki.domainname.de

We use a nginx reverse proxy and SSL so is set in the configfile xwiki.cfg

xwiki.home=https://wiki.domainname.de
xwiki.url.protocol=https