I am logged into toolsadmin.wikimedia.org and see this on https://toolsadmin.wikimedia.org/profile/settings/accounts/:
I am loosing access to my "@fu-berlin.de" address, so I'd like to update everything to "@mailbox.org". I have managed to do so, partially, as you can see on the screenshot.
For the "Wikimedia account" section, I need to find the email settings for the Wikimedia Meta Wiki and then click "Refresh OAuth credentials here"
For the "Phabricator account" I neede to find the email settings in Phabricator and it got synced here.
I can't seem to find any place to update the email for "Wikimedia developer account" though.
I have already logged into idm.wikimedia.org and updated the email there. Also this ldap page shows the correct address: https://ldap.toolforge.org/user/sebkur