I got a bounced email

If you got a message with the subject Undelivered Mail Returned to Sender, the recipient’s server refused the email you sent.

What to do

Looking after your domain’s reputation is very important to keep your emails getting through.

• Don’t resend the same message several times.
• Check that the recipient’s address was typed correctly.
• Ask the recipient, through another channel, whether they changed their address.
• If the problem continues, contact our support and forward the bounced message.

Understand why it was refused

The reason is usually written in the body of the bounced message. Each provider words it differently, so below are the most common reasons and examples of how they appear.

The address doesn’t exist

The address you tried to reach doesn’t exist or was deleted.

Examples:

• mailbox not found
• Requested mail action aborted, mailbox not found
• Address unknown
• The email account that you tried to reach does not exist.

The recipient’s mailbox is disabled

The recipient’s mailbox was disabled or suspended.

Example: This mailbox is disabled

The recipient’s mailbox is full

There’s no space in the recipient’s mailbox to receive your message.

Examples: Not enough disk space, Mailbox full, Quota exceeded

The recipient is getting too many messages

The recipient’s address is getting many messages at the same time, which is common during a spam attack. For safety, their provider refuses new messages for a while.

Example: Recipient is receiving email too quickly

The message was refused without a clear reason

Some refusals are generic. The provider may have considered the message spam, or your address may have a poor reputation with that provider.

Examples:

• recipient rejected
• 550 5.0.0 Message Rejected
• 550 Administrative prohibition - envelope blocked