Will the mailbox ever be re-enabled?

It's possible if the user resolves an issue with their provider, but for bulk senders, it's safer to treat it as a permanent hard bounce.

What is a recycled spam trap?

ISPs sometimes take old, abandoned email addresses, disable them (returning 5.2.1), and later quietly re-enable them to catch senders who don't clean their lists. Anyone sending to the re-enabled address is flagged as a spammer.

← Error library

550 5.2.1 Mailbox disabled

permanent Hard Bounce

Meaning

The recipient's mailbox exists but is disabled and not accepting messages.

Common causes

The user's account has been suspended by their administrator or email provider.
The account is inactive due to long-term non-use.
The user is receiving email at a rate that triggered an automatic suspension.

How to fix

Remove the email address from your mailing list.
Do not continue to send to disabled mailboxes, as they may eventually be turned into recycled spam traps.
If the recipient is a customer, prompt them to update their email address upon their next login.

Provider notes

Gmail. Returns 'The email account that you tried to reach is inactive.'

Example bounce

550 5.2.1 The email account that you tried to reach is inactive.

FAQ

Will the mailbox ever be re-enabled?: It's possible if the user resolves an issue with their provider, but for bulk senders, it's safer to treat it as a permanent hard bounce.
What is a recycled spam trap?: ISPs sometimes take old, abandoned email addresses, disable them (returning 5.2.1), and later quietly re-enable them to catch senders who don't clean their lists. Anyone sending to the re-enabled address is flagged as a spammer.