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Email activity

Addresses checked before sending

Why some mail is refused because the address doesn't exist, and how to keep your list clean.

What this is

Before we send, we check whether the address can receive email. If the mailbox doesn't exist, or its domain takes no mail at all, we don't send. You see "Not sent — this address doesn't exist (checked before sending)".

Mail to an address that doesn't exist can never arrive. Each attempt still counts against you. The recipient's provider marks you down, and outbound filters treat a sender that mails many missing addresses as a spammer. Refusing those messages keeps the rest of your mail reaching inboxes.

You are not charged for mail we refuse this way.

How it works

  • SMTP and API sends. A message to an address that doesn't exist is refused as it is sent:Nothing is queued, and nothing reaches the recipient's provider.
  • Campaigns. The recipient is skipped and shown in the report as Not sent — address doesn't exist. The rest of the campaign goes out as normal.
  • Imports. New contacts are checked in the background after an import. The import screen shows how many don't exist and how many are risky. Addresses that don't exist are marked Doesn't exist and are never mailed.
  • Marketing mail sent over SMTP. A new address may wait a few minutes while it is checked. After that, the message is sent even if the check hasn't finished. Transactional mail, such as password resets and receipts, is never held.

Risky is a warning, not a refusal. It covers three kinds of address:

  • throwaway addresses (10-minute mail);
  • domains that accept every address whether or not it exists;
  • role addresses such as info@ or sales@.

Marketing mail to throwaway addresses is not sent; it counts on your Deliverability page as "throwaway". Everything else is sent as usual.

If a check can't be completed, the mail is sent exactly as it would have been. A check never delays or loses mail because we couldn't finish it.

Set it up

There is nothing to switch on. To send fewer messages to addresses that don't exist in the first place:

  1. Confirm addresses when people sign up (double opt-in). Send one email with a link, and only add the address once the link is clicked. This is the single best defence: typos and made-up addresses never reach your list.
  2. Check for typos at the form. gmail.con, gmial.com and hotmial.com are the usual culprits.
  3. Remove addresses that bounce. We do this for you automatically — see Suppressions.
  4. Don't mail lists you didn't collect yourself. Bought and scraped lists are full of dead and trap addresses.

When something is wrong

Your app got a 550 5.1.1 … does not exist (checked before sending) reply. Remove the address from your list. The mailbox doesn't exist, and sending again gets the same answer.

A campaign shows many "Not sent — address doesn't exist". The list has old or mistyped addresses. Those recipients were skipped and you were not charged; clean the list at its source.

You're certain an address is real. Contact Mailyte support with the address and we'll check it again. Addresses at a domain that had no mail server are checked again automatically after 30 days.

Imported contacts show "Doesn't exist". The address was checked after the import and doesn't exist. Correct the address if it was mistyped, or remove the contact.