How to fix Soft Bounces

What is a Soft Bounce?

SMTP2GO categorizes bounced emails as either 'Soft' or 'Hard' by analyzing error messages sent to us by the recipient's mail server. A soft bounce typically occurs when there is a temporary problem with the recipient mail server and the email cannot be accepted at that point in time. Where possible, we will attempt delivery a number of times until it bounces or times out.

Common causes for soft bounces can be due to a recipient's mailbox being full/over quota, a mailbox provider may be experiencing a temporary issue or a heavy load, or it could be due to spam filtering or reputation-related issues (domain or IP on a blocklist).

To view specific soft bounce reasons, go to your 'Reports > Activity' page, select the soft bounced email and then view the 'Timeline' tab. The 'Timeline' tab will show you all delivery attempts and the final soft bounce message that we received from the recipient's incoming server. The responses differ depending on the recipient server but they often give a clear reason in regard to why the email failed.




Soft Bounce examples:

  • Recipient address rejected: Mailbox full
  • The email account that you tried to reach is over quota.
  • Service unavailable - try again later
  • This message was blocked because its content presents a potential security issue.
  • Message bounced due to organizational settings.
  • Message rejected due to local policy.
  • Unroutable domain: could not be found on the internet, please re-check the email address.

How do I resolve a Soft Bounce?

The recipient will need to resolve the soft bouncing issue from their side. You may need to make alternative contact asking them to investigate and you can provide them with the bounce response their server is giving to help them resolve the issue. You can attempt to send an email to them again anytime.

Can Soft Bounces be resent?

Once an email soft bounces, it won't be resent and there is no option to resend that from in the SMTP2GO account. The bounce is the final result for the email and it would need to be sent again from the sending software.


If you encounter bounces that you would like assistance with, please contact our support team with specific examples and we will investigate for you.


Was this article helpful?