Email marketing today – nope, it’s not just about spammers trying to mislead hapless email users to click and buy their products – is a legitimate tool for retailers to reach their consumers effectively without treading on their privacy, cluttering their space, or eating up their time. But before your emails reach your consumers and claim their attention, there are certain best practices that you can follow to make sure your emails reach your consumers healthily.

This article describes best practices for the following categories:

  1. The Email List
  2. The Email Sending Infrastructure
  3. The Email Content

The Email List

The Email list is the base from where you start your campaigns. It is very important to ensure that the list contains only active consumers who are interested in receiving your emails.

How do you collect email ids?

There are multiple guidelines to be followed to ensure interests of both the retailers and (especially) consumers. What are the correct ways of collecting email ids for your marketing campaign?who are you- rapenzil

The two important things to consider while collecting email ids are:

1. Informing your customers about how you intend to use the email ids collected from them.

2. Obtaining consent from customers that they are okay with the arrangement.

It is recommended that the disclosure should include information such as type and frequency of messages and whether the sharing of their email ids would result in any implication for the consumer.

There are multiple practices of obtaining consent; each practice comes with a different degree of freedom I2and convenience.

  • Double Opt-IN: In Double Opt-In, the consumer who has explicitly opted in for receiving your emails is sent a welcome email with a link and the customer’s opt-in to your emails is confirmed only when he/she confirms manually by clicking the link.
  • Opt-IN with verification: With this option, the consumer who has explicitly opted in for your email services is sent a welcome email disclosing the intent of how the email might be used. The customer is also provided with a link to unsubscribe from receiving your emails.
  • Opt-IN: In Opt-In, the consumer can explicitly opt-in to your email services by providing his/her email id.

There are a few cases where an Opt-in is not considered explicitly, but doing business with the retailer and providing the email address assumes consent. In cases of referrals, it is recommended that the retailer sends a welcome email requesting for explicit consent. The practice that one chooses depends on the convenience and feasibility. However, it is important to keep in mind that sending an email to an uninterested consumer is a simple waste of bandwidth and hence the above options should not be used to manipulate and grow one’s email list artificially.

The law of the land also can decide to whom you can send or not send emails. “Do not Contact” or equivalent lists could be maintained by the government or associated 3rd party where the users can specify their generic preferences for getting promotional content on their emails. Not abiding by such laws can be catastrophical.

How good is your email list?

Once you have a list, it is important to ensure its validity. The following are few causes that affects the quality of your email list which in turn affects the quality of your campaign.

Invalid emails

I3The consumer who was obligated to provide an email might give you a non-existing email address. There may be human errors in recording the email address correctly due to typos and other mistakes. These errors can be prevented if your email collection follows the double Opt-IN method. However that may not be possible for many practical reasons such as the turn-around times required for double Opt-INs.

Spending on bandwidth and sending marketing messages to non-existing emails is just a small and innocent part of the problem. The bigger and more serious problem is, having a significant portion of invalid email addresses in your mailing list that makes the ISPs suspicious of you as a sender. In their endeavor to keep the interest of their users, ISPs will block messages, including the legitimate ones coming from such senders. They may blacklist you or apply more scrutiny on your messages. Neither is a good news for a sender and gaining back your reputation would be a hard task.

So, ensure a clean list by removing all those emails that bounce with 5xx error indicating it as an unreachable email.

Inactive emails

I4Many retailers carry records of their consumers for years, and it is possible that the email ids have gone inactive over time.

Issues caused by using inactive emails is similar to invalid emails, but can be more serious if an inactive email is used as Spam-trap by ISPs. ISPs again in their endeavor to keep the best interest of their users are always on the look out for spammers to black-list them. One of the spam-traps used is to check if messages are being sent to old, unused, or inactive emails and classify such senders as spammers.

Temporarily inactive email ids

These are also called Soft bounces where the email account is unable to receive the emails and the issue is temporary. However, it is important to keep track of such errors and weed out the emails if the error doesn’t resolve in a reasonable period of time or number of attempts.I5

The email servers, especially those with private firewalls and proxies that are often used by corporations may not provide the correct error messages and/or use the correct format for rejecting your email and repeated attempt to send even after multiple rejections would further affect the reputation of a sender.

The best ways to ensure your email list is valid and current is to

  • Weed out the bouncing emails (hard and soft bounces mentioned above).
  • Check whether there is an explicit unsubscribe link that efficiently processes such requests so that no more emails are sent to such users.
  • Set up feedback loops with ISPs to get spam reports (report of cases where the user has marked your email as spam) and unsubscribe such users.I6

If you are importing email list from an older system without these practices, it is recommended that the email list is whitelisted* before they are used in the newer system. This way they would not adversely affect the reputation of the newer system.

*Whitelisting is a method where 3rd party vendors validate the email list to remove Invalid and Inactive email list without actually sending emails.

The Email Sending Infrastructure

The most important thing apart from being a legitimate source and being responsible for the emails you send to the consumers is to able to prove to the ISPs that you are a legitimate entity.

The following measures are highly recommended.

Prove your legitimacy as an entity

Have a registered domain that points to a real website that describes who you are, what you do and how you can be contacted.I8

  1. It is important to have an existence that can be verifiable by standardised means. In the email world this means you ensure your registered domain is “Public” for Whois (
  2. For few reasons businesses might want to keep their information “Private” or “Anonymous”. Make sure your reasons are good enough to absorb the price of having bad email deliverability.
  3. Email servers considers everyone guilty unless proven otherwise. Spammers don’t have websites that lists down what they do and how to contact them. Having a valid website with clear information about your business, privacy policy and contact information ups your trustworthiness by several points.

Everything is linked and nothing is dangling

  1. SPF Validation ( Assume consumers trust the domain of the sender, but how do they know that this mail is really sent by  the retailer and that they are not being spoofed? So it is important to whitelist the physical host machine (IP) that is used for sending the email as authorized by the sending domain.I9
  2. Reverse DNS lookup ( The domain confirms that a specific IP address is sending the email. But can consumers get a reconfirmation by asking the same question going through the IP address just to be sure?I10
  3. DKIM verification ( The consumers trust the sender domain and know that the machine sending the mail belongs to the retailer. But how do consumers know that this particular mail is sent by the retailer? DKIM verifies that the mail coming from a specific domain is authorized by the domain administrators and not spoofed enroute.I11


  1. Include DMARC ( The retailer must include SPF and DKIM even before someone asks these questions, thus making it easy for the verifiers.

Don’t just send but be open to receive

1. Provide a clear and easy access for the user to Unsubscribe and honor the choice:I12

  • Don’t hide the option or don’t make it extra difficult. This will only encourage the user to mark you as a spammer. If the email users are marking you a spammer, none of the measures you take to ensure your legitimacy counts.
  • Try collecting information about the reason behind unsubscription without adding too much to the process to fine-tune your communications. Some questions can be about Frequency of the emails; Content of the emails; and Relevancy of the emails that may have changed over time.

2. Configure abuse@ and postmaster@ email addresses

  • These are the standard emails that every sender should provide so that the receivers can complain when they feel fit.
  • Provide working addresses and act on the emails received by responding and/or unsubscribing the user as appropriate.

Create a secure setup for sending emails

  1. Use dedicated IP address to send your message so that the receivers can associate your credentials and your reputation is not diluted by misdeeds of other senders.
  2. Warm up your IP address by sending few hundreds of messages regularly for few weeks before increasing the traffic so the receiving world gets used to your presence by clearing the pipe with checks and verifications when the traffic is small.
  3. Make sure you operate in a secure environment and do not route your emails through open relays or proxies.

The Email Content

The email content that gets scrutinized by email servers is a little about the message and a lot about its format. The following practices separate you from spammers who have to hide their content and cannot afford some of these methods.

Ensure your email format is perfect

  1. Abide by all the HTML rules:


  • Do not forget to close your tags, write the HTML code in lowercase, add alternative attributes of your images etc.
  • HTML is lenient on these errors and won’t spoil the end user experience. However, Spam filters are grammar Nazis and are not too kind on violators.
  1. Use Pre-Headers to your advantage:L2
  • Pre-headers are few lines of text that are used by many clients, which are displayed along with the subject line. This enables users to read the text before opening the email.
  • Pre-headers must be put to good use. They must convey the content of the email and get the attention of the users. When not particularly considered, this often displays text version of the HTML such as “Click here to see..” etc which wastes a golden opportunity.
  1. Check your rendering in different email clients:

Email clients expect perfection from others but are unapologetic about their own bugs or not supportive of standard practices, which could break your email appearance even though your HTML is perfect.L3

  • Example, Gmail does not support <style> tags … </ style>, Outlook does not handle background images and CSS3 is still supported by very few clients.
  • Bad rendering means consumers are missing your message and are more prone to marking your email as SPAM.

 Ensure your email contains readable textL4

  1. Make sure your email is not all about images. Images cannot be verified by spam filters and doesn’t allow email servers to categorize your content (which would result in being categorized as the worst possible content).
  2. If your email content is HTML, ensure the Text format is attached. Not all email servers can display or want to display HTML.
  3. Email servers often would like to compare HTML content to Text content to ensure nothing is hiding behind HTML formatting.

Essentials about the message inside

Finally keep an eye on the message itself to make sure it does not offend the security checks enroute.

Keep the following things in mind while creating an email:

  1. Avoid IP address based or shortened links:
  • Spammers often hide behind such links that do not make the identity of the landing page apparent. Hence, avoid temptation to shorten the link to make it look better and never consider IP address link.
  1. Make your identity very clear to your users:L5
  • Use your branding and website prominently in the email content.
  • Avoid using Noreply@ address for sending the emails. Ensure users can always reply to your emails.
  1. Avoid the words frequently used by Spammers and get your Spam score before you send:
  • Unfortunately there are many innocent words that suggest Spam/phishing such as “Free”, “Urgent”, “Click here”, “Promotion” etc.
  • Use spam filters to understand the risks for the given content. Each spam filter reacts differently to the content of your emails. So test your content with multiple filters and avoid the super set of errors.
  • SpamAssassin, VadeRetro, Cloudmark, Barracuda, Postini etc are few filters that you can use.
  • Email clients (Outlook, Thunderbird) and webmails have their own filters too that can be used to test your content.  So before sending your email, understand what works and what is risky to include in your content creation process.

*** All the best and happy email marketing ***