Quick answer
Email Users → Export → Plusvibe. In Plusvibe, go to Email Accounts → Import → Upload CSV.
What's next
Frequently asked questions
Should I use Plusvibe warming or Winnr warming?
Pick one — running both wastes budget without meaningful gains. Winnr's is included in your subscription add-on ($0.60/mailbox/mo); Plusvibe's is external and priced separately.