Understanding and Managing Bounces This document describes the situations that can cause a Silverpop email message to bounce, and how you can manage these bounces from within the Marketer 5.0 application. What causes bounces? Invalid and Inactive Email Addresses Even email addresses that have been directly provided to you by customers or prospects may become invalid. Someone may change jobs or change his or her Internet Service Provider (from AOL to Earthlink, for example) and get a new email address in the process. It is very unlikely that this person will update his or her email address on all the lists to which he or she is subscribed. In other cases, someone may have provided you with an email address that is still valid, but is no longer active. This frequently occurs with web-based email accounts, such as Hotmail and Yahoo. Web-based email accounts usually have size limitations on them. If the account user does not check the account very often, unread messages will accumulate and cause the account to exceed its limitations. The account provider will often deactivate the account until the user removes some of the messages. Situations such as these can cause email delivery to fail, resulting in a “bounce”. There are basically two phases to the delivery of an email message during which bounces can occur: delivery from one server to another, and delivery from the recipient server to therecipient’s mailbox. Send Server to Mail Server In the first phase of message delivery, the server sending the email communicates with the server handling incoming messages for the recipient’s domain (the part following the “@” in a recipient’s email address). For example, when you send a mailing from Marketer 5.0 the send server is Silverpop’s SMTP server. That server communicates with a mail server for each recipient domain on the list (for example yahoo.com). If the domain lookup fails, or if the domain’s mail server rejects the requested connection a bounce will occur. The most likely causes for the domain lookup to fail are the domain name being incorrect, invalid, or expired. In addition to domain lookup failure or failure to connect, the mail server might reject the message communication for a number of other reason. For example, the mail server might not be functioning or might be overloaded. The mail server could also be configured to reject any requests from a particular SMTP server. This is a commonly known practice in the email industry referred to as “blacklisting”. Silverpop does everything it can to prevent messages from our domain from being blacklisted. Mail Server to Mailbox The second phase of message delivery deals with the transfer of the message from the mail server to the appropriate mailbox. A bounce may occur during this process if the intended recipient does not exist on this mail server, or if the recipient’s account has been deactivated, possibly due to inactivity or exceeding its mailbox size limitations. Hard and Soft Bounces Silverpop reports bounces as belonging to one of two categories: hard or soft bounces. We rely on communications received from recipient's email servers to determine the type of bounce that occurred when those servers refuse to deliver a message to a recipient. All bounces are handled by PMTA. Based on the Port 25 best practices, PMTA does the following: 1. Invalid address errors are immediately bounced 2. Invalid domains, not reachable domains etc. are retried every 5 minutes for 12 hours before being bounced. 3. Valid addresses, valid domains and delivery errors (such as mailbox full) are bounced on receipt of the notice 4. Mail blocks etc. are bounced immediately. Hard bounces are reported for messages that are returned from the recipient email server with the indication that the recipient account does not exist. Soft bounces are reported for messages returned with the indication that the message was accepted by the recipient's email server, but was not able to be delivered to their account. This can be caused be a variety of issues. For example, the recipient's account may be over its limit for messages in the Inbox or it may have exceeded the amount of storage space reserved for it on the server. Soft bounces are also reported for messages that were never accepted by the recipient email server. This can also be caused by a variety of issues. For instance, an email server that is temporarily offline or a server that temporarily refuses to accept email would cause a soft bounce. Invalid domains can also cause soft bounces. Please keep in mind that some mail servers (particularly older servers) are configured incorrectly and do not send bounce information to the correct location (for example, they may send the bounce back to the “from” address rather than the “bounce” address specified in the mail header). In this case, Silverpop will not be notified that the message bounced. Managing Bounce Data Tracking Must Be Enabled For individualized bounce data to be available, tracking must be enabled for the mailing. Otherwise, only aggregate bounce data will be available. Accessing Bounce Data To look up bounce data for a particular mailing, follow these steps: 1. Navigate to the Reports section. 2. Click on the Mailing Reports link 3. Select you mailing from the list 4. All bounce information for the mailing is housed under the Delivery Info section. You can view total bounce statistics and access detailed data by clicking the Soft Bounces or Hard Bounces links. Exporting Soft Bounce Data To export soft bounce data for a specific mailing, follow these steps: 1. Navigate to the Reports section. 2. Click on the Mailing Reports link 3. Select you mailing from the list All bounce information for the mailing is housed under the Delivery Info section. You can view total bounce statistics and access detailed data by clicking the Soft Bounces or Hard Bounces links. Click on either the links, and you'll be presented with an option to "Create a List from these Addresses". The list will be stored in your mailing list folder. Note: This option is only available if tracking was enabled for the message. You will only be able to export soft bounce data if you have not deleted the original list to which the mailing was sent. Opting-out Bounce Addresses If you want to prevent yourself from mailing to bounced addresses but do not want to remove them from your list, you can choose to opt-out the bounced address from your list. To do this, navigate to your bounce data screen and click the Opt-out button. Purging Bounce Addresses Purging addresses from your mailing list will prevent you from attempting to send to those recipients when you use the same mailing list in the future. To purge bounces from your list, you can create a list of bounces and use the Purge List function in the List section to purge them from your list. Just click on the Purge List link, select the list you want to purge bounces from, and select the list you created from your Mailing Report (this list will be stored in your Stored Files under the Export Files section. Note: This option is only available if tracking was enabled for the message. Recommendations Avoiding Blacklisting One of the reasons that a domain may blacklist a send server stems from repeated sends to invalid addresses. Many administrators see repeted sends to invalid address as an indicator of spamming. For this reason, you should pay attention to bounce data when sending repeatedly to the same mailing list. Re-sending to Soft Bounces Soft bounces may occur because of temporary conditions; the recipient may empty their mailbox, for example. The Silverpop send server will re-try the address if you have applied the appropriate soft bounce retry settings. To do this, first create a list of the soft bounce addresses as described above. Then purge the addresses from your original mailing list. Re-send your mailing to the soft bounce list. If you wish, repeat this process: generate a new list of soft bounces from the previous soft-bounce list, and send to the new list. You should re-try the same addresses only one or two times, unless you have reason to believe that the mailing should go through and that there are exceptional circumstances preventing its delivery.