Gmail may ask for verification to add a forwarding address or edit filters

Filters: creating a brand new filter, enhancing an current filter, or importing filters. 

Forwarding: Including a brand new forwarding tackle from the Forwarding and POP/IMAP settings. 

IMAP entry: Enabling the IMAP entry standing from the settings. (Workspace admins management whether or not this setting is seen to finish customers or not)