What is the difference between "hard" and "soft" bouncing, and if they reactivate, do they come off the list?

bounce, or bounce-back, is an e-mail that is returned to you because it cannot be delivered for some reason. You've probably gotten bounces on your own personal e-mail program, when you send an e-mail and then receive a response saying it was undeliverable. These get to be more of a headache, however, when you publish an e-zine. Sending e-mail to more people means more bounce-backs. And too many bounce-backs can cause your mailings to be blocked with certain Internet service providers, meaning many of your e-mails won't reach your readers. What You Need to Know There are two kinds of e-mail bounces: A hard bounce is an e-mail message that has been returned to you because the recipient's address is invalid. A hard bounce might occur because the domain name doesn't exist, the recipient is unknown, or there's some type of network problem on the recipient's end. A soft bounce is an e-mail message that gets as far as the recipient's mail server, but is bounced back before it reaches the recipient. One of the most common causes for a soft bounce is a full mailbox. This will happen A LOT with your subscribers who use free e-mail services like Yahoo and HotMail, because they allow for very little e-mail storage. What You Need to Do Ask your current list service how they handle your bounces. Some of them have a hands-off policy and don't do anything. If so, ask them how you can go in yourself and see how many names are bouncing and who they are. Then you can decide to keep them on your list or delete them. One factor to consider here is your listserve's "retry" policy. That is, how many times do they try to send out your e-zine to the soft-bounce people? Some only try once, others try several times, waiting a few hours in between. Sometimes you'll also see a few e-mail addresses that are obviously misspelled (e.g. "nancy123@aolcom" -- note the missing dot) and you can fix them yourself manually. If your listserve is hands-off, you'll want to go in and look at your bounce situation at least once a month to check things out and delete names if necessary. The other extreme is list services that automatically delete people after only one hard bounce, which isn't good because it could be caused by a temporary problem like a network outage. If this is your listserve's policy, find out if you can change it. Then some list services take the middle road by automatically deleting anyone who has had a certain number of bounces in a row. Ideally you want them to wait longer on soft bounces to make sure that the problem isn't resolved over the next few issues you send out. You can often instruct the listserve to unsubscribe soft bounces after a specific time, say, five bounces over a two-week period.

What’s the difference between a "hard bounce" and "soft bounce"? http://help.yahoo.com/l/us/yahoo/groups/original/ownmod/email/email-21.html Hard Bounce We consider your member's account to be "hard bouncing" if the error message we get back from your member's email provider says either of the following: email account doesn’t exist ISP refuses all email from Yahoo! Groups. In this case, your member's Yahoo! Groups account will be deactivated and set to "Bouncing." They won’t receive any group email until their account is reactivated. Learn how to reactivate their account here. Soft Bounce If the error message we get back from your member's email provider doesn't fall under the definition of a hard bounce, then the error is considered a soft bounce. If the account generates an occasional soft bounce error, it will be logged but no other action will be taken by Yahoo! Groups. However, if the email account consistently generates soft bounce errors for several days, then that Yahoo! Groups account will be considered bouncing and will be deactivated. In this case, your member won’t receive any group email until their account is reactivated.