CeeTrust currently lists 37 login portals used by people in Germany — covering workplace (31), webmail (2), education (1), government (1). Each "official site" link below has been checked manually against the organisation's own domain, with no aggregators or third-party login wrappers.
If you reach a portal page from a search and the address bar shows something different from what you expect, close the tab and start again from the organisation's main website. Look-alike domains are how phishing pages work; the safer path is always to type the name of the bank, school, agency or company you want into the URL bar, not into Google.