listEmailAccounts discovers mailboxes you can use for sequence enrollment.
automations/list-apollo-mailboxes.automation.ts
account. Returns { emailAccounts }; each mailbox
includes id, email, aliases, active/default state, thresholds and delays,
provider, owner, synchronization, revocation, and deliverability metadata when
Apollo supplies it. Pass { id: emailAccount.id } to sequence actions to skip
mailbox lookup.