Looking for logging into the Otrs 5 Message site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Otrs 5 Message site. After that you can login as usual with your login credentials.
http://doc.otrs.com/doc/manual/admin/6.0/de/html/ConfigReference_Section_Frontend_Customer.html
https://doc.otrs.com/doc/manual/admin/5.0/de/html/email-settings.html
https://doc.otrs.com/doc/manual/admin/6.0/en/html/ConfigReference_Section_Frontend_Customer.html
https://doc.otrs.com/doc/manual/admin/6.0/en/html/ConfigReference_Section_Core_SystemMaintenance.html
https://otrsteam.ideascale.com/a/dtd/An-information-banner-on-the-customer-portal/354070-10369
ftp://ftp.otrs.org/pub/otrs/doc/doc-admin/5.0/de/pdf/otrs_admin_book.pdf
https://groups.google.com/forum/#!topic/otrs_archive/DqqcQwsgtCM
https://wikitech.wikimedia.org/wiki/OTRS
https://rrzk.uni-koeln.de/sites/rrzk/Daten_speichern_teilen_verwalten/otrs/Kurzdoku_OTRS_5.pdf
https://www.linuxquestions.org/questions/linux-software-2/customer-login-otrs-make-postmaster-default-927368/
https://doc.otrs.com/doc/manual/admin/6.0/en/html/first-login.html
https://doc.otrs.com/doc/manual/admin/6.0/en/html/ConfigReference_Section_Frontend_Agent.html
https://dev.ib.pl/ib/otrs/commit/d1a9954533c4db299bf6d2b261b4ee9b71de2cd0?view=parallel