An email that is rejected by an email server for a temporary reason. An email may soft bounce if a mailbox is full, the recipient email server is down or offline, or the email message is too large.

Building a Highly-targeted Opt in List: When Money Lies Beneath the Lists
Are you successful with your Internet business? Better yet, do you think you are successful with your online business? When most online entrepreneurs are asked with these questions, they often brush it off.