1. List segmentation is key: seperate your openers

All subscribers are important, but the engaged subscribers are without a doubt the most important. We define an opener as a subscriber who opened his email and did not report it as SPAM or unsubscribed from your list.

We suggest separating the openers from the rest of your subscribers and dealing with them as premium customers on premium IP’s and sending domains.

There are several methods for separating openers and non openers and they are mostly done by the ESP (Email Service Provider) and it should not be your concern but it should be your demand.


IP management best practices

Premium IP’s and domains are those IP’s and domains which sends only high quality traffic with high open rates and low complaint rates. it is hard to know the exact figures but as a rule of thumb if the IP sends emails and less than 6% of the emails are opened then that is not a premium IP. subscribers who marked email as SPAM have a big effect on delivery.

Bottom line: separate the openers from the rest of your subscribers, it can be with different IP’s and sending domains or even with different suppliers.

2. Always use a clear unsubscribe link

Sending to subscribers who do not want to receive your email will hurt your delivery because some will complain and press the “mark as SPAM” button and this will sharply decrease the delivery rates.

Subscribers’ complaints are a big obstacle to email delivery and in some cases can block you completely. We highly suggest making sure that the unsubscribe link is clear, working, easy to use and immediate.

A subscriber does not deserve to get 3 more emails just because the technical operation takes 2 days instead of 2 seconds.

Bottom line: Increase delivery by having a clear unsubscribe link.

3. Do not write SPAMMY content

The only parameter you control completely is the content of your email. There are certain words and signs (like “FREE”, “$$$” or “WIN!!”) that will get your email thrown into the SPAM folder even with premium IP’s and sending domains.

There are many tools to check for SPAMMY content (like mail-tester) but from our experience, if you think there are some words and signs that can get you into the SPAM folder, then send a test email to yourself and check whether it goes into your inbox. It is very important to notice that different ISP’s like Gmail and Yahoo have different SPAM filters so you should take that under consideration.

spam tips

Bottom line: If you are not sure your content is “SPAM free”, check it yourself and make sure before sending the campaign. It is one of the most important email marketing best practices.

4. Text to image ratio

It is not only words that make a difference, sometimes the email can land in the SPAM folder because of a bad text to image ratio. Text to image ratio is the ratio between the text you write in the email body and the size of the picture you send in the email.


text to image ratio

Text to image ratio is one of those parameters that ISP’s like Gmail or Yahoo calculate in their SPAM algorithms. ISP’s assume that spammers send big pictures with a few words so when you send a similar email, you are at risk of going into the SPAM folder.

Bottom line: Pay extra attention when you send an email with a large picture and just a few words.

When you include pictures in your email, add extra text – this may be the difference between an inbox and a SPAM folder – This tip is very important for subscribers with a Yahoo account because Yahoo pays extra attention for this issue.

5. Email configuration SPF, DKIM, rDNS – So what the h#ll are they? Should I worry about it?

These are a common types of email authentication methods implemented on the IP’s and sending domains. They are extremely important for delivery. As an email marketer you don’t need to handle them, but you do need to worry about them.

In fact email configurations are one of the most important factors ISP’s calculate when trying to decide of an email delivery. All of these acronyms are email and domain authentications that help the ISP to know for certain the sender is a permitted sender which is allowed to send from the sending domain, or not.

It is always the Email Marketing Provider (ESP) responsibility to make sure that the sending IP’s are authenticated properly with the sending domains and that none of them were blacklisted.IP management best practices are crucial to email delivery.

email configuration

So what the h#ll are they?

SPF: This is an acronym for “Sender Policy Framework” and it is the most common and most basic email validation system. You create one by adding a simple TXT record in the DNS zone claiming which IP’s are authorized senders for the specific domain. Without SPF chances of delivery are really low.

DKIM: This is an acronym for “DomainKeys Identified Mail” and it is another email validation system but not as common as SPF. Not all ESP’s use DKIM since they are sometimes considered as “nice to have” and they take more time to configure than SPF. Few ISP’s give a very high score to DKIM and without it, landing in the inbox after 2K will be quite a challenge, AOL is a good example for this kind of an ISP.

rDNS: This is an acronym for “Reverse DNS” and it is a way to determine which domain is associated with a specific IP. It is a very good practice to have rDNS on all the sending domains.

Bottom line: Make sure your ESP is getting his hands dirty and making sure everything is properly configured. It is probably the most important parameter for email delivery.

6. Sender reputation

Sender reputation is an indication of the trustworthiness of an email sender’s IP address. Sender reputation is very important, but it’s very hard to keep track of. The reason is that sender reputation varies from one ISP to another. A senders’ reputation in Gmail is not the same as the one in Yahoo.


sender reputation

You can track your sender score with the ReturnPath senderscore.org tool, but we found a weak correlation between their score and actual open rates.

Bottom line: The best way to keep a good reputation is to follow email marketing best practices and check the open rates per ISP.

7. IP management best practices: Shared IP’s VS. Dedicated IP’s which one is better ?

First let’s explain what does these 2 options mean:

• Shared IP’s: As we mentioned before each email is sent from a specific IP, when you choose an option of “shared IP’s” it means your emails are sent via IP’s that are sending other emails as well. Shared IP’s can be a good idea if you still do not have a good email reputation and you are just starting out. It can be a really bad idea if the rest of the emails which are sent contain bad traffic with lousy open rates .

• Dedicated IP’s: This means the traffic is from these IP’s are yours and yours alone. In this case you are not affected by other emails and you basically determine your own destiny.

In our experience, the best thing to do will be to have your own dedicated IP’s and slowly warming them up with good traffic of openers. This will result in very good, stable and slowly increasing open rates.

Bottom line: Use dedicated IP’s and gain more reputation as time goes by.