Email Deliverability FAQ

ContentMX Email Deliverability, Knowledge Base

Why am I not receiving email that I am sending to myself? Why are people within our company not receiving the email?

It is not uncommon for email you send to yourself from ContentMX to be blocked by email filters. This happens when you are sending an email FROM your company domain TO email addresses within that same domain. Many email protection systems see this as an attempt to spoof your email (pretending to be you) and will block the email. Often times this is not detectable through the Email Activity report, the email is simply accepted by your mail server but never delivered to the inbox.

You can confirm this situation is causing your delivery problem by temporarily changing the FROM address you are using when sending the email through ContentMX. The simple way to do this is to click the “Change Sender Information…” link when you are preparing to send your email. Select the “Use alternate based on a selected user” option and choose ‘noreply@contentmx.com’ as the user. With this setting, your message will be sent from a ContentMX email address and not your own.  Next, click to send a test message to your email address. If the email is received, you have confirmed that your email filter is the culprit and you will need to ask your IT person to make a quick change to allow your emails through.

It is important to note that this situation is specific to your company and it does not mean other people outside your organization are also having this problem.

It is fairly easy to fix this issue. Most anti-spam firewalls provide the ability to whitelist certain domains and/or IP addresses. You will need to provide the IP address and domain used by our mail server so that it can be added to your whitelist.

What are the IP addresses you use to send email so that I can whitelist them?

Test messages and network mailings come from our primary mail service. The domain and IP address pointing to this server are:

o1.smtp.butterflypublisher.com [208.117.49.62]

Why do recipients sometimes see “via butterflypublisher.com” or “On Behalf Of” as part of the FROM address in their email program?

This information appears because we are providing the email authentication needed for the deliverability and security of your email campaigns.

How authentication works

By default, it is fairly easy to forge your identity when sending email. All you do is set the FROM address and name to whatever name you would like. For instance, anyone can pretend to be a bank or credit card company. Authentication techniques help prevent this from happening. An authenticated email clearly indicates who is sending an email and which mail servers have the authority to send it. Email servers can check the authenticity of an email, and if it fails the check the email can be blocked or marked as spam.

The most common types of email authentication are DKIM (Domain Keys Identified Mail) and SPF (Sender Policy Framework). Services like AOL, Gmail and Yahoo and many corporate mail servers use one or more of these authentication methods to verify sender identity.

ContentMX makes the process of authenticating email simple because we authenticate all of your email for you. This is why the “via butterflypublisher.com” may appear as part of the from address. The email is being sent on your behalf by us, and butterflypublisher.com is the authorized sender.

Can I authenticate my own emails? YES!

Yes, this is possible, but it requires a slightly more advanced implementation. Contact us if this is required and you have access to the advanced technical resources needed to do this. This will allow us to authenticate the emails we send for your domain using DKIM.

SPF authentication is handled by including our email service domain in your SPF record which is stored as a TXT entry in your DNS. Our email service domain is contentmx.net. For example, you would add a TXT record like this to your DNS server:

v=spf1 mx a include:exampledomain.com include:contentmx.net ~all

What should I do if someone else outside our company is not receiving our email?

There are many reasons someone may not receive your email. The first step is to check some simple things:

  • Is the email address on the mailing list?
  • Is the email address correctly entered?
  • Was the mailing processed or was it scheduled to be run later?

Once a properly addressed email is sent from the ContentMX server there are a few things that could happen:

  • The destination domain may be invalid.
  • The destination mailbox may not exist, is disabled, or full.
  • The email server at the destination domain might be temporarily down (and the system will try again later).
  • The spam filtering on the destination domain may reject the email and cause it to bounce back (which is visible in the Email Activity report).
  • The spam filtering on the destination domain may drop the email without notifying anyone.
  • The spam filtering on the destination domain may filter the email and place it in a spam folder, bulk mail folder, or (in the case of Gmail) in the Promotions tab.

How do I figure out what is happening?

Check Bulk Email Folder and/or Promotions Tab

First have your contact look for the email in their bulk mail folder or Promotions tab. If it is there, the email has arrived properly. Email newsletters coming from email marketing systems are often labeled as promotions and bulk mail. This email appear with other email of this type.

Check the Spam Folder

If the email is still not found, have your contact check their spam folder. If the email is there, have your contact move the email out of the spam folder and then ask them to add your FROM email address to their contacts list. This should keep your email from re-entering the spam folder next time.

Contact Our Deliverability Team

If the email is not anywhere to be found, send an email to support@contentmx.com to ask our deliverability team for help. With this support request you should provide the username to access your account, the date and time of your mailing, and the email address for the contacts who did not receive your email. We will use this information to check our email server logs more closely.

At the same time, have your contact reach out to the person responsible for their email server. This is usually the IT department or help desk. They may need to provide the FROM address you used when sending the email along with the approximate time and date you sent the mailing. With this information, the mail server administrator should be able to review their own logs to determine what happened to the message. The response from the server administrator will help determine the next step.

How can I prevent my email from being blocked, dropped, or categorized as spam?

There are many techniques for dealing with deliverability issues. This is more of an art form than a science. Sometimes email can be blocked because of structural issues such as IP or domain restrictions, send frequency, message size, failed authentication, spam complaints, etc.. It is also common for email to be blocked based on content. Most anti-spam technology has at least one component that reviews the content of the email and rates how spammy it is based on the words it contains.

If you are experiencing issues relating to content, here are a few things to try:

  • Have the recipient contact their mail server administrator and add the FROM address domain or our IP address to the White List of their Spam Filtering technology. Our mail server can be found here: o1.smtp.butterflypublisher.com [208.117.49.62].
  • Have the recipient add the FROM address to their Address Book.
  • Try a different FROM address and name.
  • Change your email subject line and remove words that may be too promotional.
  • Change your email body. Avoid an email that is only pictures, keep it short, and avoid too many promotional words.
  • Still stuck? Contact us at support@contentmx.com and we will run some tests on your content and recommend changes.

Why do I have so many bounces? Why is the number of emails delivered so much less than the number of recipients?

A bounce occurs when the ContentMX mail server is unable to find a destination or receives feedback from the destination server that the email cannot be delivered. The most common reason for a bounce is that the email box no longer exists.

Bounce rates can vary depending on a number of factors including the age of the list, how frequently you are emailing the list, and the method used to build the list.

If you send to a mailing list that has not been used in a few months or more, the bounce rate will be much higher when you send your first mailing. There is a natural churn on an email list that will build up over time. Once you start sending your mailings on a regular basis, the bounce rate should return to a normal level.

Over time, you will also notice that the number of emails delivered will become increasingly less than the number of recipients to which you are sending your message. This occurs because previously bounced email addresses are automatically handled by the server and subtracted from a mailing. For example, if you have a list of 1,000 recipients and 20 emails bounced on the first mailing and then 10 emails bounced on the second mailing, on the second mailing the delivered statistic would be somewhere around 970.  NOTE: Do not try to do the math. The mail server reports delivery confirmations and bounces separately. It is possible for a message to produce no bounce or delivery confirmation.