E-Mail Headers: Where the Action Is
The most important part of an e-mail message may be something outside of the creative process: the e-mail header. How to decipher it.
The most important part of an e-mail message may be something outside of the creative process: the e-mail header. How to decipher it.
As email marketers, we spend a majority of our time creating email bodies. However, the most important part of a message may be something outside the creative process: the email header, those generally hidden lines of code at the top of each message.
Now that the email industry is using authentication, reputation, and accreditation, the email header plays a critical role in an ISP’s decision to block or deliver a message. Most of us, though, let our IT departments or email service providers (ESPs) worry about the header.
With our basic walkthrough, you can interpret what the header tells you about message delivery. We’ll also provide a couple reasons fiddling with some list software settings can actually hurt deliverability.
(If you’re reading this via email, you can follow along by viewing this message’s full header. In Outlook, open the message. In the drop-down menu, select “View,” then “Options.” In Gmail, select the “More Options” link, then the “Show original” link located below the subject line. Most email clients, especially Web clients, show shortened or even no headers unless you change the setting.)
Following is some key information included in most email headers:
If you want to identify the server name and IP address that sent this message, look at the topmost received line. Here, the message was sent by “web32708.mail.mud.yahoo.com” from 68.142.207.252.
This is where a deliverability problem can crop up. Are you still using the old email hack that changes the current date and time to a phony future or past date to make the message show up at the top of the inbox? Better change it back to the current date and time now. Many anti-spam programs check the creation date when evaluating your message’s legitimacy and reject messages sent from dates too far in the future or past. You should also show the recipient’s actual email address in this line instead of a general message, such as “Newsletter Recipients.”
Based on the content-type, you can see this message is in plain text format, written with the ISO-8859-1 character set, and encoded in 8bit. Messages sent in foreign languages would reflect the appropriate encoding format and character set.
This message was scanned by SpamAssassin, version 2.64. It scored -4.0, meaning it’s unlikely to be spam or fraudulent. If the message had violated any spam tests or rules, those would be reported here.
This last bit of information can also help you test a message before you deliver it to your full list. (You do test, right?) Test your message in different browsers and email clients; they display email, especially HTML email, differently. The header data in the test messages will also tell you whether the email encounters any problems in transmission or delivery.
You still have to worry whether a particular word or line of HTML coding in the message body could trigger a spam filter. But knowing how to interpret the data in an email header will help make it easier to avoid future transmission.
And as always, keep on deliverin’.
Want more email marketing information? ClickZ E-Mail Reference is an archive of all our email columns, organized by topic.