Confused about hard bounces, soft bounces, or rejected emails? Here’s the lowdown…
SMTP2GO categorizes all bounces into hard bounces and soft bounces. A rejected email is an email that SMTP2GO blocks due to the recipient being on your suppression list.
We do the hard/soft categorization by analyzing the error message sent to us by the recipient’s mail server. If the message indicates that there is no chance that the email address will work in the future, it is classified as a hard bounce.
Examples of hard bounce error messages:
The email account that you tried to reach does not exist. User unknown This user doesn't have a yahoo.com account
Examples of soft bounce error messages:
Recipient address rejected: Mailbox full The email account that you tried to reach is over quota. This message was blocked because its content presents a potential security issue.
Our system automatically blocks (for a period of 7 days) any attempt to send to an email address that has hard-bounced. This is an important policy: if we continually tried to send emails to hard-bouncing email addresses, we would very quickly damage our reputation in the email community. After 7 days, the hard-bounced email address will be automatically unblocked and sending can resume. If there are still issues with the recipient email address, however, it will hard-bounce time and time again. You should, therefore, remove hard-bouncing email addresses from your local mailing list.
We record blocked attempts to send emails and call these rejected emails. Rejected emails are attempts to send emails to any email address that has hard-bounced within the past 7 days, has previously reported an email as spam, has previously unsubscribed, or has been manually added as a suppression. You should aim to have zero rejected emails.
If you find a hard bounce that you think may work again, you can unblock it from the Reports > Suppressions page in your SMTP2GO control panel.
Email addresses that have soft-bounced are not blocked by our system, as soft bounces usually indicate a temporary issue that can potentially self-resolve.
In some instances, after a successful delivery, a Hard Bounce could be recorded. This will usually mean that the original recipient was simply forwarding email to a different mailbox. These forwarded emails almost always bounce as domain authentication is not aligned. In most cases, you would not know about said bounced email. However, with SMTP2GO, the use of Variable Envelope Return Path verification (VERP), which is the newest form of verification will give you an insight into more logs after initial delivery.
Note: an email that has bounced (either hard or soft) will not be retried. The bounce is the final result of the email.
If you have any questions about bounces or rejected emails, please contact our friendly support team at firstname.lastname@example.org.