Apple Mail (iCloud) 550 5.1.1: inactive account.

The mailbox exists but has been temporarily deactivated by the user.

How to fix 550 5.1.1.

Retrying or final
Final
A 5xx reply. The server will not accept this message. Resending it unchanged fails again.
Who is at fault
Recipient
The address, the mailbox, or the recipient’s own mail rules.
Severity
WarningInactive Account
Permanent550 5.1.1

iCloud allows users to pause an address. The mailbox may reopen, so treat the bounce as temporary unless it persists for weeks.

Next steps

  1. 1Retry in your normal soft-bounce cadence for the next few campaigns.
  2. 2Suppress the address after repeated failures across multiple sends.
  3. 3Encourage subscribers to reactivate or provide an alternate address.
  4. 4Run re-engagement campaigns before contacts hit the inactivity window.
Apple Mail (iCloud) documentationEvery raw SMTP 550 reply

The same code at other providers.

Providers word the same code differently. Their fixes differ too.

550-5.1.1GmailRecipient address does not existFinal
550 5.1.1 LPN007_416Laposte.netInvalid recipientFinal
550 5.1.1SFRUser unknownFinal

More Apple Mail (iCloud) codes.

Full Apple Mail (iCloud) playbook

Other Apple Mail (iCloud) fixes

421 4.7.1Rate limitingRetrying
550 5.1.1User does not existFinal
user is overquotaMailbox full (user is overquota)Check the reply
554 5.7.1 [HME1]Authentication failureFinal
554 5.7.1DMARC failureFinal
550 5.7.0Proofpoint blockFinal

In the glossary

Bounce (Hard)Hard bounce is when an email cannot be delivered because the address is invalid or blocked. It is a permanent failure and the address should be removed from your list.
Suppression ListA suppression list is the place your email tool keeps addresses that should not receive messages. It is a permanent "do not send" list that helps you avoid emailing people who have opted out or caused issues in the past.
List HygieneList hygiene is the practice of cleaning your email list by removing bad or inactive addresses. It keeps your list focused on people who still want your emails.
Bounce RateBounce rate is the percentage of emails that could not be delivered to recipients. It shows how many addresses are invalid or blocked compared to the total you tried to send.

Browse all raw Apple replies →

More references.

SMTP field manual.

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