Mailpro does not sell a separate "automation plan" with unlimited workflows — because it does not need one. Building and running automations is included with every Mailpro account. You can create as many workflows as you want, with no per-workflow fee. You only pay for the emails or SMS that the automations actually send, at the same rate as your regular campaigns.
How automation pricing actually works
One email sent by an automation = one email credit, exactly like a campaign. One SMS sent by an automation = one SMS credit, same rate by country as your regular SMS. Triggers, tag actions, list actions, internal alerts and waits are free. The "unlimited" piece you might be looking for is already there — unlimited automations, unlimited steps, no monthly automation fee.
Why no separate automation plan
Charging per workflow would penalise smart structure — splitting a giant flow into three clean smaller ones would suddenly triple your bill. Charging per fire would make trigger-heavy designs (every tag change for example) expensive even when they cost us nothing. Tying cost to the message itself keeps things predictable.
If you want unlimited message-credits
That is a separate question, and the answer depends on volume. Check the email pricing and SMS pricing, then add automatic credit recharge if your monthly volume is hard to predict. Unused credits also roll over month to month.
Run as many automations as you want
Browse the automation actions, set the credit budget that matches your volume on the pricing page, and forget per-workflow fees.