were you trying this ?
https://graph.microsoft.com/v1.0/me/events?$filter=organizer/emailAddress/address eq 'test#example.com'
According to the graph documentation. it is not yet supported.
Unfortunately, filtering by organizer email address is not supported yet and there is no plan to change it in the upcoming months. As a workaround, filtering by organizer name is supported.
https://github.com/microsoftgraph/microsoft-graph-docs-contrib/issues/8259#issuecomment-1680828412
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