Soft bounce means that the email reached the recipient's server but got bounced back without reaching the recipient's mailbox. Soft bounce indicates that email delivery failed for a temporary reason.
Reasons causing soft bounces to happen
- Recipient's mailbox is full
- Problems with the mail server of the recipient
- Oversized email message
- "Away" settings of the mailbox set by its owner. This usually happens when someone goes on vacation and does not wish to be disturbed by emails.
Unlike hard bounces, soft bounces still have a chance of delivery if the sender resends the soft-bounced email after a certain period of time. Depending on the reason for delivery failure, the messages can be delivered.
For example, if the mailbox was full and then the owner cleared their inbox, the email can be delivered on the second try.
Or, when the problems with the recipient's server have been resolved and it started functioning again, the soft bounce email can be delivered.