Bounce protection

Bounce protection checks each new contact's email address before we email it. We ask the person's mail server if the mailbox exists. Nothing is sent to them.

This matters because mail to an address that doesn't exist bounces. Too many bounces and we pause your sending:

If 3 or more of every 100 emails you send in an hour bounce, we pause your sending for 6 hours. If it keeps happening because of addresses that don't exist, the pauses get longer.

Bounce protection finds those addresses before you email them, so we never send to them.

What a check is. One check is one address answered. Each answer uses one check:

• Deliverable — the mailbox exists.
• Risky — it may not take mail. For example a shared address like info@, a throwaway address, or an inbox that is full.
• Doesn't exist — no mailbox, or the domain takes no mail. We never email it.

Couldn't confirm costs nothing. The check is given back. Adding an address that is already a contact costs nothing too.

Where your checks come from. We use them in this order:

1. This month's checks from your Marketing plan: 1,000 on Starter, 5,000 on Growth, 25,000 on Premium. They don't carry over to next month.
2. Checks you bought. They never expire.
3. Send credits you bought or were given before checks launched, at 10 credits a check. Credits you buy now are for email only.

When all three run out, new contacts are still added. They are marked Not checked, and we email you once.

When it is on. Every new contact uses one check: added in the dashboard, imported, or added by your app. A contact whose address changes is checked again. If your app adds people who still have to confirm, we check them when they confirm. Addresses that don't exist are marked Doesn't exist and never emailed.

When it is off. New contacts are added as Not checked. We still tell you, free, about how many look bad. Finding out which ones uses checks.

The pause. Every bounce counts toward the 6-hour pause: an address that doesn't exist, a full inbox, or a server that blocks us. Only addresses that don't exist make a marketing pause longer. If addresses that don't exist cause a second pause within 30 days, it lasts 24 hours. A third stops marketing until your list is cleaned. A pause of your app's email and your mailboxes lasts 6 hours and never grows.

Inbox full. Sometimes a check finds the mailbox is full. The contact shows Inbox full, and the date the hold ends.

This person's mailbox has no space. Mail will bounce until they clear it. We hold marketing to them for 7 days, then check again.

Your app's emails still go. A bounce from a full inbox still counts toward the 6-hour pause. It never makes a pause longer.

1. Open Sending, then the Bounce protection tab. It shows the switch and how many checks you have left.
2. Turn the switch on. It starts on if your plan includes checks. Only an owner or admin can change it. If you don't use Marketing, there is no switch: it checks contacts, and contacts are part of Marketing. Step 4 is the one for you.
3. If you need more checks, buy them in Billing. Bought checks never expire.
4. Ask your developer to check addresses when people sign up. Give them Check an address at signup.

Contacts you had before checks launched are checked once by us, for free. You don't need to do anything.

You're out of checks. New contacts are added as Not checked. Buy checks in Billing. Then, in Contacts or Email verification, check the contacts that were missed.

Your marketing is paused. A banner tells you why and until when. Turn on Bounce protection and check your contacts to start sending again sooner. If your contacts are all checked, the pause ends by itself at the time on the banner.

Your marketing is stopped. Addresses that don't exist caused three pauses in 30 days. Check your contacts, or remove the ones that aren't checked. The banner has both. If your contacts are all checked, make sure Bounce protection is on. If marketing is still stopped a few minutes later, contact support.

Your app's email and your mailboxes are paused. It ends by itself after 6 hours. Every bounce counts, so look at what bounced in Email logs. To make it less likely, check each new user's email when they sign up: see Check an address at signup.

A contact shows Inbox full. You don't need to do anything. We check again before the date shown, for free.

The switch won't change. Only an owner or admin can change it. Ask one of them.

An address you know is real shows Doesn't exist. Send yourself a test to it. If it arrives, contact support with the address.

• Check an address at signup — for your developer
• Email verification — check a list, or your contacts
• Addresses checked before sending — what we refuse before it goes out
• Contacts — where checked addresses live
• Go to Bounce protection