When an email fails to be delivered to an email account, it is called a bounce. Email bounces can be caused by a multitude of reasons. These reasons are commonly grouped into two types; hard bounces and soft bounces.
A hard bounce is an email that couldn't be delivered for a reason that is deemed to represent a permanent failure.
Common reasons for hard bounces include:
- Recipient email address doesn't exist.
- Domain name within the email address doesn't exist.
- Recipient email server has completely blocked delivery.
- Mailbox has been in a full state for a long period of time, such that the email provider has determined that the email account has been abandoned by the user.
If the bounced email address is still valid (for example with respect to the mailbox being full for a long period of time) and the contact wishes to recommence receiving your emails, they can 'un-bounce' themselves via the following steps:
- Open up a previous email received from you via Enudge.
- Click on Update your Preferences option located in the footer of the email.
- Click the UN-BOUNCE MY EMAIL button in the update screen.
Alternatively, you can send an email to Enudge requesting that the person's email address is reinstated - please send such requests to email@example.com.
How does Enudge treat hard bounces?
- They are excluded from all future campaign sends, for all users of Enudge.
- You cannot add bounced contacts to your campaigns - they will be omitted.
You can see which email addresses of your contacts have hard bounced via the Enudge Bounce report (see Quick Links menu or the reports drop down in the Contacts screen).
Enudge will not allow you to send again to an email address that has hard bounced because doing so can damage the reputation of Enudge as a trustworthy sender.
A soft bounce refers to an email which was not delivered due to temporary deliverability failures. Some common reasons are:
- Mailbox is full (exceeded quota).
- Recipient's email server is down or offline.
- Message blocked due to its content. Refer to this article for some useful content-related tips to help with deliverability.
- Message does not meet the recipient server’s:
- DKIM requirements for authentication. Read this article to find out more about DKIM and how to implement this technique to improve deliverability.
- anti-spam settings.
- anti-virus filters.
- allowed senders list.
- other policies including content policies.
While there are remedies for some of the causes mentioned above (e.g. DKIM, content-related bounces), other causes require configuration changes by the recipients email server.
How does Enudge treat soft bounces?
You can continue to send to email addresses for which a soft bounce occurred.