Auto responder limits on your plan
Starter allows one email per auto responder; Base and Pro have no cap. Sends come out of your normal allowance, so multiply steps by contacts.
Updated
Two separate limits apply to auto responders: how many emails one can contain, and how many sends you have available. They are unrelated, and either can stop you.
Emails per auto responder
Starter allows one email per auto responder. Base and Pro have no limit.
A one-email responder is still useful. It's a welcome email that goes out the moment someone joins a list, while they still remember signing up. But it's not a sequence. Adding a second email on Starter returns “This auto responder has reached your plan’s email limit. Compare plans to add more.”
You can have more than one auto responder on Starter. The cap is on emails within each.
Sends come out of your normal allowance
Auto responder emails are not a separate pool. They draw on the same allowance a campaign does, against every limit your plan carries. On Starter that's per hour, per day, per month, and how many different people you reach in a month. Base has a monthly limit only, and Pro has none.
The arithmetic catches people out. A four-email sequence reaching 300 contacts is 1,200 sends, not 300. Multiply steps by people before you activate, especially if you're enrolling a list you already had.
Before you pick a plan
You can build and activate an auto responder before choosing a plan, and people who join the list are enrolled as usual. Their emails wait until you pick a plan, then go out from where they stopped.
What happens when you run out
Sending pauses. The responder stays active and nobody is dropped from it, but the emails that were due are held until your allowance has room again, then delivery resumes from where it stopped.
The monthly unique-recipient limit on Starter behaves slightly differently. Once you reach it, auto responder sending stops rather than trickling, and it picks up again as sends older than 30 days age out. If your responder goes quiet while your monthly send count still looks fine, this is usually why.
The Billing section of this help center covers how the limits interact.
On the Free plan?
The Free plan is no longer available to new accounts. Accounts that already had it keep it for as long as they stay on it, with the same limits as Starter, including one email per auto responder.
Raising the limits
Base and Pro remove the per-responder email cap and lift the send limits. You can compare them from Billing in your settings, or from the Compare plans link on the Auto Responders page.