The email sending process in Mailbox has been improved with more specific notifications and better error handling to prevent duplicate emails and make it easier to recover messages that could not be sent.
When sending an email from the Send Email window, if an address is invalid or rejected by the server, the message is sent to the remaining recipients, and a notification identifies the addresses that could not receive it.
If the server rejects all recipient addresses, the message is not sent, and the notification lists the rejected addresses.
When sending fails, the notification specifies whether the server rejected the message, requested that the user try again later, or rejected the account. The email window preserves the message content so the user can retry.
If the server rejects the account or the provider of a connected Google or Microsoft account does not accept the message, the notification directs the user to Email Accounts to review or reconnect the account.
Emails that have already been sent are no longer marked as failed solely because the server did not confirm delivery, helping prevent duplicate sends.
Recipient addresses that could not receive the email are not added to recipient suggestions.
These improvements provide clearer information about sending failures, preserve messages when errors occur, and reduce the risk of duplicate emails.