Recently a well-known email marketing executive called us up to share her excitement about her new viral campaign. We were psyched too; viral friend-tell-a-friend campaigns can be such a powerful tactic to grow your opt-in email list.
Then our Tech Editor, Alexis Gutzman, started eyeing the way the marketer's viral email was being sent. Turns out, the way the email was sent meant that many big ISPs would filter it out as "suspected spam" before it got to the recipient.
The whole problem had to do with the way the message "header" was set up. It is something every email marketer should be aware of, especially if you have a tell-a-friend function on your site or if you use a third party email broadcast firm.
Here is a column on the header problem by Alexis. Read it over yourself, and then pass it on to the tech team who send your broadcast email.
-> Yes, Spam Filtering Affects Opt-In Emailers Too
Spam has increased by more than 600% in the past year. To cope with the influx, ISPs such as AOL, Mindspring and Verizon, as well as most big company IT/MIS departments are using spam filters.
This affects legitimate broadcast emailers, such as opt-in email marketers and email newsletter publishers, because there is no set way these various spam filters can know if the email is requested opt-in or not. Currently the filters can only guess at what is spam. Which means legitimate email gets caught up in the net along with its less legitimate cousins sometimes.
To avoid being filtered, first you have to know that there are three ways that ISPs filter spam:
1. By looking at the header of the message
2. By looking at the contents of the subject line or message body to identify likely spam words and phrases
3. By subscribing to a blacklist service that provides an up-to- date list of domains that have been identified as being used by spammers
Today we are going to explain how to avoid being filtered based on your headers. (We will cover avoiding the other two ways in future issues.)
-> Are Your Messages Already Being Filtered Out?
Are you already being filtered based on your headers? Unfortunately there is no way to tell exactly how much of your broadcast email is being filtered prior to reaching it's intended recipients.
Some ISPs that filter at the server level will send your message back to you as a "bounceback." But not all. In fact AOL, among others, does not send back filtered messages. (Another reason why if you have a large slice of AOL email addresses on your list, make sure you add a "seed" name of your own there to see if mail gets through properly.)
Sometimes a lower-than-expected open or click rate will tip you off that you have a filtering problem. Make sure that you routinely check these metrics on a regular basis.
Luckily, even if you are not sure how much of your email broadcast is being filtered, header filtering is one of the easiest things to fix.
-> Headers Are Your Calling Card
Back when society was more civilized, you would visit an acquaintance and hand your calling card to the butler. While you waited patiently, your calling card would be delivered to the acquaintance, who would decide whether he or she wanted to receive you.
In the email universe, your calling card is your header, and the butler is the recipient’s mail server.
When you send a message to someone on your list, a conversation takes place between your email server and your recipient’s. Your email server sends the recipient’s email server just your header (the FROM email address in your email message). If the recipient’s email server does not like the way your header looks, it will reject your message.
One way filters evaluate your header is by making sure it's the same as the actual domain that is sending the email.
For example, if the FROM email address claims to be “email@example.com,” but the email server from which the message is sent is “spamcentral.com,” then the email server can reasonably assume that the header has been falsified.
This sounds trivial, but falsifying headers can get you into big legal trouble, as some ISPs including AOL have strict terms and conditions for anyone sending them email and explicitly say that they will delete mail with falsified headers and will prosecute (and have successfully prosecuted) offenders.
When you send bulk email, it is easy to change the FROM address, but it is much more complicated to disguise the identity of the sending mail server. Spam filters understand this. They believe the domain information. They do not believe the FROM address, nor should they.
-> Alert: You May Be Falsifying By Mistake
There are two scenarios under which you might be inadvertently falsifying your header, without even realizing it is happening.
Scenario #1: You send email using a third party broadcast email service (aka a "list host"), and you put your own FROM email address, rather than a FROM address on the third party's server.
If you send email from a list host, make sure that the FROM email address is one that is hosted on their mail server. Ask them to assign you one.
Yes, you can still put your FROM name as your own name. You still should put your own email address as the REPLY-TO address. Most human replies will go to the REPLY-TO address, rather than the FROM address. Bounce messages often go to the FROM address (or the BOUNCE address, if you set one up for that purpose).
Scenario #2: You have a “forward to a friend” feature on your site or email messages, and when it sends email, it uses the referring friend's email address as the FROM email address rather than yours.
We certainly see the logic of having the forwarded message come FROM the trusted party. It is more likely to be opened, for one thing, but this can get you into big trouble.
Quick fix: Rather than sending the message FROM the friend's email address, send it FROM an address on your email server.
Be sure to use the friend's name at the start of the subject line of the message, and the friend's email in the REPLY-TO address. These two things will increase your open rates and pass- along success.
However, we do want you to be aware that by forcing the first friend to enter an email address, a first name, and a friend’s email address, in order to use your forward function, you might have raised the barriers too high for him or her to use the feature.
Our best-practices workaround is a bit on the technical side, so it is in the Tech Notes.
-> Boring But Necessary Technical Notes:
If you want to use an address on your own server for the FROM address, set up an MX record on your Web server with a third-level domain that points to the mail server of your list host.
For example, we have the address lists.marketingsherpa.com that actually resolves (in the DNS) to our list host. Since the recipient’s mail server will frequently check the DNS to make sure your domain exists. Since lists.marketingsherpa.com resolves to the IP address it is coming from, the messages go through no problem.
By having this MX record set up, you can have all subscribe and unsubscribe messages also appearing to go through your own domain, rather than firstname.lastname@example.org.
As part of testing your email campaign, you should have test accounts set up with ISPs that filter on each of these bases mentioned above, so that you can test what is getting blocked on a regular basis. (We will cover testing in much more detail in a future issue.)
If you see any messages in your delivery report from recipients’ mail servers that “malformed headers” or something like that, it may be that you are being filtered on this basis.
-> Best-practices recommendation for forwarding to a friend:
If you have a “forward to a friend” feature in your email message, include a hidden field in the forward form to hold the recipient’s email address.
You obviously have the recipient’s email address, since you are sending the message to that address. When your reader clicks “send” on the forward form, your server will know who is doing the sending and will be able to apply the right REPLY-TO address without having to ask for it.
This feature won’t work on your Web site unless you have cookies in place with visitors’ email addresses, which is something you might want to think about adding. It is relatively trivial to update your cookies with email information from an HTML newsletter or from the opt-in thank-you page on your Web site.
The views and opinions expressed in the articles of this website are strictly those of the author and do not necessarily reflect in any way the views of MarketingSherpa, its affiliates, or its employees.