The Bulk Email module for DotNetNuke has a feature known as Bounce Email Monitoring, and it is probably a good idea to understand what it does and how it does it so we can explain how best to configure it.

Sending a Bulk Email Message

When an email message is generated using the DotNetNuke Bulk Email Module, a list of all the email addresses that you have selected from multiple sources is generated into a database.

The lists that you select can include.

• Website Users
• Custom Lists that you import
• Microsoft CRM Marketing Lists
• Imported contacts from email programs
• Custom typed email address

Once the list is complied, email addresses are removed.

• Duplications
• Email addresses on the unsubscribed list
• Email addresses on the bounce email list (that meet the requirements set)

Then the email messages are sent out and ticked off as being sent.

You can see that bounced email addresses will only be removed if they are on the bounced email list, and have bounced to a count matched the settings configured.

How the Bounce Email List is Generated and Counted

Periodically, the module will use the setting for the POP 3 account to look for email messages that it can add as a bounce. To do this, it will download all messages in the mailbox and look using some complex searching tools for email messages that appear to have bounced back from a failed send attempt.

Unfortunately email servers report bounce messages in different ways, so the code that reads the email messages and looks for bounce backs is long and complex. For this reason, the process of finding bounce messages should be kept to a minimum to reduce the load on the server.

Reduce Load

The best way to reduce load is to minimise the number of mail messages that the process needs to check.

The best way to do this is three fold.

1. Send email from a unique email address that suggests no normal communication should run through that account. noreply@domain.com is my suggestion. That way the only email messages in that mailbox should only ever be bounced messages.
2. Delete processes messages. The module can do this for you, but if the mailbox is a normal account, then ensure it is basically kept empty.
3. Manually delete messages that are not bounce messages. If you intent to use a general account, then you should keep it as free as possible from general communications.

What happens if you don’t do this?

The process of downloading thousands of email messages, checking them all and processing them all can take hours. It will put a huge load on both the web server and your email server. It will increase your data transfer costs both on your web and email server.

So follow the suggestions and the result should be clean and fast.

Want to know more about email messaging in DotNetNuke.

Today we have added support to the DotNetNuke Bulk Emailer module for WebFarms.

We have identified a feature of Bulk Emailer for DotNetNuke that has caused some issues with the running of the module on a WebFarm.

There is an automatic enable feature that checks when you start a bulk email message that the scheduler for the module in the Host / Scheduler is enabled. If it is not enabled, the module will enable it.

The Problem

With WebFarms there are two processes that run at the same time.

This will cause duplication of sending email messages.

The solution is easy… just disable one of the schedule processes. However this will be automatically re-enabled by the module.

The Fix

To solve this we have added an option to the Bulk Emailer Settings. This option enables you to tick that you are using a WebFarm, stopping the automatic enabling of iWebs BulkEmailer EmailSchedule process.

Additional Steps Required

After you enable WebFarm mode, you will need to go into the Host Scheduler processes and disable all but one of the multiple processes for the iWebs BulkEmailer EmailSchedule.

The result will be that only one of the schedulers run and only one email message will be sent.

If you are using the Advanced Email Module for DotNeTNuke, called bulk emailer, and you find that the links you place in your emails are not working when they arrive as an email. Then the fix is simple.

In the Bulk Emailer Settings Menu

Click on the option to Update Link

This will force the module to operate on the URL that you are currently working with on the site. It is necessary when you install the module in a dev URL and then try to operate through another URL such as a final domain name url.

The help for the item reads:

If you change the domain name that this module is operating on, then you should click ‘Update Links’ to reset the base URL for Email Tracking, Unsubscription and View Online.

One of the most common problems experienced by users of hosted email services is that they find they can only send email messages to their own domain.

For Example, if you have two hosted email addresses:

1. ted@mybusiness.com
2. john@mybusiness.com

You find that you can successfully send an email message from one user to another, but when you try to send to any other domain:

1. anything@hotmail.com

You find that the email messages do not send.

Solution

You need to enable “Authentication” in your configured email account settings. There are many client email programs, probably the most common is Outlook.

When you configure an new POP3 email account you normally end up with something that looks like this:

If you click on More Settings / Outgoing Server

and just tick the option to use the same settings as the incoming mail server.

This is all that is needed to enable outbound SMTP authentication.

Background

SMTP Servers (or email servers) are setup to need stop people using them for sending email messages. As strange as that sounds, if they were not setup this way, then anyone could SPAM the world using that email server.

To prevent users from abusing an Open Relay Mail Server, the administrators say that anyone wanting to send email messages from that server to any other server, will need a users name and pass. Almost always this is the same user and pass as the one needed to download your mail from that server.

This this need for user and pass is referred to as “Authentication” and is necessary on almost all servers, other than internet service providers who give you an internet connection. In that instance they authenticate you from your internet connection.

Why Can You Send to Your Own Domain?

Because Email Servers by nature will received email messages to addresses they host. This is part of the process necessary for email messages to be sent and received.

DNN SMTP Settings

DNN Websites have the ability to configure in the host settings an SMTP server. When a DNN email is generated from the DNN website, it will attempt to send mail through this SMTP server.

In order that your DNN website can successfully send the email, the SMTP server must allow the email message to be received. Typically this is done in one of four ways.

1. The SMTP server is configured for Open Relay (This should NEVER be done unless you have an external firewall blocking all external SMTP connections. Otherwise your mail server will become a spam server within hours)
2. SMTP Authentication – Typically SMTP servers are configured to allow users with a valid username and password to authenticate themselves. Once they have been authenticated, they can communicate email messages through the SMTP server. This is the same way most ISP’s work their mail servers. The idea is that only users who are customers of the ISP will allow email to be sent from their SMTP servers.
3. Selective Open Relay. The administrator of the SMTP server can also allow Open Relay (same as 1 above) from selective IP addresses. Any communication from an IP address that is configured to allow open relay will be accepted by the SMTP server.
4. Local Host – If your website has it’s own SMTP server configured, typically it will allow email message to be sent form it’s self.

To correctly configure your DNN SMTP settings, you need to understand what method of communication has been configured in the SMTP server you are trying to set DNN to access.

Here is the process you would configure from above.

1. Enter the IP address or valid domain name for the SMTP server, nothing more to do if open relay is allowed. (Still not recommended)
2. Enter the IP address or valid domain name for the SMTP server, and the valid user name and password as would be used to communicate with the SMTP server. This is where you get to use the user name and password setting in DNN.
3. Ensure that the SMTP administrator has allowed the IP address your DNN website uses to have open relay status. Then just enter the IP address or domain name of the SMTP server in your DNN host settings.
4. Configure your DNN host settings to have “localhost” in the DNN SMTP server settings are.

Problems.
There can be some issues that get confusing with the different methods.

1. Open relay mail servers will be attacked by spammers very quickly. They are always on the lookout for mail servers that they can abuse. It is never recommended to have your mail server on the internet and in open relay. Additionally your mail server will be blacklisted by other mail servers if found to be in open relay.
2. SMTP Authentication  can still be restricted to certain IP addresses. Many ISP’s will allow you only to use their mail servers while you are a client of their AND connecting to their mail server from an IP address they own. So thing will work in your Email applications while you are connecting to the internet via their dialup or high speed connection, but as soon as you move away from a connection provided by them, you will not be allows to connect to their servers, let alone Authenticate.
3. Even if your ISP has allowed relay from the address that your mail server is run form, there may be a firewall or block on the normal port that the SMTP servers are typically configured to use. Port 25. If a firewall exists between your web server and the mail server, it must be configured to allow traffic over port 25.
4. You may have web server configured with an SMTP server on the same system. Yet have it be blocked over port 25 for outbound communications. Some ISP’s block port 25 to curb the flow of virus email messages. You need to be sure that your ISP that provides connection to the internet for your web and SMTP server is not blocking port 25.

How to get really confused.
Often mail servers will allow you to send email messages to email addresses on that SMTP server, even though they do not allow you to send mail out. So if you have a web application configured to send email to yourself, and the SMTP settings you use in the DNN host settings are for the SMTP server that runs the same email address you will have success.
Yet when you change the email address in the web application, you can no longer send email, and the web application appears to fail. This is still an SMTP configuration error on your website. You will need to find a method above to solve the issue.

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