Managing DSNs & bounces

Managing DSN or Bounces is a critical step for building efficient emailing campaigns. This article aims at giving some clues to successfully handle this problem.

Summary:

Introduction

Definitions

Scenarios

Manage DSNs in the Global Script (advanced user)

First, there are few important things to understand:

This article will help you to retrieve the appropriate information from a DSNs allowing you to process them efficiently. However, it is important to know that only 60% of SMTP Servers delivers Standard DSNs. This means that the clues that we will give you below are only relevant for 60% of the SMTP Server.
The different scenarios described below help you to configure how to process DSNs once they are in your project inbox. Therefore, we assume that you have already configured:
1. The incoming queues: DSNs are sent to the SMTP sender address defined in the Header Properties. Therefore, you must associate your project with the incoming queues corresponding to this address.
2. The Download conditions: Specifies which messages has to be downloaded within the project inbox.
Below, you will find three different scenarios:
1. Scenario 1: When I receive a failed DSN, I want to increment by 1 a DSN field located in my data source and I want to add in a DSN comments field the reason why the delivery failed.
2. Scenario 2: When I receive a failed DSN with a permanent failure (= hard bounce), I want to delete the record from my data source.
3. Scenario 3: When I receive a DSN, I want to increment by 1 a DSN field located in my data source and delete the record when this counter reaches 5.

Definitions: A DSN is a message created by the recipient mail server that provides informations on the current status of the message you sent and gives you access to the following data:

DSN Type: a DSN can have 5 different types:

Delivered: Indicates that the message has been sussessfully delivered. For receiving this DSN type, you need to indicate that you want to receive success DSNs in the mailer DSN properties.
Relayed: If you have indicated in the mailer DSN properties that you want to receive DSN when the message is delivered (see above), the relayed DSN type warns you that the receiving mail server does not create DSN for successful delivery.
Expanded: Indicates that the message has been sussessfully delivered but forwarded directly to other email addresses. Therefore, it is possible that you receive new DSNs regarding the same message.
Failed: Indicates that the message delivery has failed. This can be due to many circumstances. To refine the processing of failed DSN according to these circumstances, see the Scenarios below.
Delayed: Indicates that the message has not been successfully delivered but that the mail server is still trying to deliver it. Therefore, it is possible that you receive new DSNs regarding the same message. The delivery can be delayed for many circumstances. To refine the processing of delayed DSN according to these circumstances, see Scenarios below.

DSN Original Recipient: The DSN Original Recipient allows you to know who was the receiver of the message.

DSN Status: The DSN Status is a code composed of three numerical fields separated by ".".

In a failed DSN, the first figure can be '4' or '5'. '5' represents a permanent failure (= hard bounce) which means that the message cannot be delivered in any way (domain does not exist, user does not exist,...). '4' represents a temporary failure (= soft bounce) which means that the message cannot be delivered for the moment (full mail box, busy SMTP Server,...). The second sub-field indicates the probable source of any delivery anomalies, and the third sub-field denotes a precise error condition, if known. In order to have a full list of the DSN Status Codes, click here.

DSN Diagnostic Code: The DSN Diagnostic code is a short sentence that defines the DSN Status.

Scenario 1: When I receive a failed DSN, I want to increment by 1 a 'DSN' field¹ located in my data source and I want to add in a 'DSN comments' field the reason why the delivery failed.

Go to Project > Message Rules > General Tab, select 'Apply the following rule(s)', click on Add and enter a name for the rule.
Conditions to perform the actions:
1. Click on Add.
2. Select "Delivery Status Notification (DSN)" and click on Next.
3. Select "Message is a DSN" and only check the "failed" box. Click on Finish.
Actions:
1. Click on Add.
2. Select "Update a record in the datasource". Click on Next.
3. Select the list where the 'DSN' and 'DSN Comments' fields are located. Click on Next.
4. A table presents you all the datasource fields available and lets you configure the actions to perform.
  
  -> In order to add in the 'DSN comments' field the reason why the delivery failed, select the 'DSN Comments' field, click on Edit and select 'DSN Diagnostic Code' in the list under 'New Value'. Click on OK.
  
  -> In order to increment the 'DSN' field by 1¹, select the 'DSN' field, click on Edit and select 'Increment by 1' under 'Update Value'. Click on OK.
  
  -> Click on Next.
5. Now, you must tell eMill which record has to be updated. For instance, when I receive a DSN regarding the message I sent to steve@emilltest.com, I want the 'DSN' field incremented by 1 for this particular recipient. Thus, click on Add, select the field where the recipient email address is located, choose 'Equal to' in the operator list and 'DSN Original Recipient'. Note that this condition is already set by default.

Scenario 2: When I receive a failed DSN with a permanent failure (= hard bounce), I want to delete the record from my data source.

From the message rules 'General' tab, click on Add and enter a name for the rule.
Conditions to perform the actions:
1. Click on Add.
2. Select "Delivery Status Notification (DSN)" and click on Next.
3. Select "Message is a DSN", check the "failed" box, check the "The status must match" box and select "5.*.* (Permanent failure)" in the list. Click on Finish.
Actions:
1. Click on Add.
2. Select "Delete a record from the datasource". Click on Next.
3. Select your receivers list and click on Next.
4. Now, you must tell eMill which record has to be deleted. For instance, when I receive a DSN regarding the message I sent to steve@emilltest.com, I want to delete this particular recipient. Thus, click on Add, select the field where the recipient email address is located, choose 'Equal to' in the operator list and 'DSN Original Recipient'. Note that this condition is already set by default.

Scenario 3: When I receive a DSN, I want to increment by 1 a DSN field¹ located in my data source and delete the record when this counter reaches 5.

From the message rules 'General' tab, click on Add and enter a name for the rule.
Conditions to perform the actions:
1. Click on Add.
2. Select "Delivery Status Notification (DSN)" and click on Next.
3. Select "Message is a DSN" and only check the "failed" box. Click on Finish.
Actions: You must configure 2 actions.

Action 1: Increment by 1 a DSN field¹
1. Click on Add.
2. Select "Update a record in the datasource". Click on Next.
3. Select the list where the 'DSN' field is located. Click on Next.
4. A table presents you all the datasource fields available and lets you configure the actions to perform.
  
  -> In order to increment the 'DSN' field by 1¹, select the 'DSN' field, click on Edit and select 'Increment by 1' under 'Update Value'. Click on OK.
  
  -> Click on Next.
5. Now, you must tell eMill which record has to be updated. For instance, when I receive a DSN regarding the message I sent to steve@emilltest.com, I want the 'DSN' field incremented by 1 for this particular recipient. Thus, click on Add, select the field where the recipient email address is located, choose 'Equal to' in the operator list and 'DSN Original Recipient'. Note that this condition is already set by default.
6. Click on Finish.
Action 2: Delete the record when this counter reaches 5.
1. Click on Add.
2. Select "Delete a record from a datasource". Click on Next.
3. Select your receivers list. Click on Next.
4. Now, you must tell eMill which and when the receiver has to be deleted.
  - Indicate which record has to be deleted. For instance, when I receive a DSN regarding the message I sent to steve@emilltest.com, I want to delete this particular recipient. Thus, click on Add, select the field where the recipient email address is located, choose 'Equal to' in the operator list and 'DSN Original Recipient'. Note that this condition is already set by default.
  
  - Indicate that the record has to be deleted only when the counter in the 'DSN' field reaches 5. Thus, click on Add, select the 'DSN' field, choose 'is higher than or equal to' in the operator list, select 'Constant Value' and enter 5 in the text field. Click on OK.
5. Click on Finish.

FAQ - I cannot configure an action to increment a field by 1 because the option 'Update value' is grayed: In order to increment a field, it must be configured to handle this kind of data. To create a column on your list with this kind of field, select your receivers list in the eMill project tree, go to the menu Project > List > Add new column. In the 'Data Type' list, choose 'Integer'.

Manage DSNs in the Global Script (advanced user):

eMill allows users who are familiar with script to manage DSNs through the Global Script (click on the collection name to access details and samples):

The Mail DSNHeaders collection allows you to access the list of DSN Headers
The Mail DSNReceivers collection allows you to access the list of DSN Receivers