Ensure Email Deliverability for Successful Campaigns – Thoughts, Strategies and Metrics

Introduction

The raison d’etre of any email campaign is that the emails reach the intended consenting recipients. Without this basic premise, any email campaign is a non-starter. Emails blocked from reaching recipients are frustrating, a waste of time and resources.

There are two points at which email is blocked.

• By the Internet Service Provider (ISP)
• By the Email Service Provider (ESP)

In this piece, we share our thoughts on the role of Internet Service Providers (ISP) in blocking emails, strategies businesses can use to minimize this, and ways to measure how effective these strategies are. This detailing of thoughts is part of Xerago’s Engineering practice, providing solutions to Improve Email Deliverability.

What is Deliverability?

Deliverability is defined as the measurable predictability, ease, and frequency with which your email is delivered to the Primary Inbox of a Verified Recipient.

Deliverability is impacted if emails do not reach recipient Inboxes. This happens when your email is blocked.

There are two points at which email is blocked.

• By the Internet Service Provider (ISP)
• By the Email Service Provider (ESP)

The path your email follows is:

Sender (or Sender ESP) → ISP → Receiver ESP → Receiver Inbox

When you dispatch emails, they traverse through ISPs before reaching mailbox providers (ESPs), ultimately making their way into users' inboxes. ISPs can obstruct the continued transmission of your emails if they perceive suspicious activity. If the ISP blocks your email, your receivers, the target audience, are simply unaware that you have sent them an email.

Insights from the Definition of “Deliverability”

Let’s break down the definition of “Deliverability” and inspect the phrases.

A. “Measurable Predictability, Ease and Frequency”

Businesses use various metrics to measure the quality of deliverability. We cover them in the contexts in which they are used.

B. “Verified Recipient”

A verified recipient is someone who has expressly consented to receive emails from you, either because of a past purchase or other interaction, or because of a confirmed opt-in to your newsletter, and acted upon it.

Since they haven’t opted to receive emails from your business, unverified recipients will consider your emails spam and label them as such. Particularly annoyed recipients will even block them. ESPs periodically send data to ISPs on emails received from domains and IP addresses that several users have either labeled spam or blocked.

Consequences of Unverified Recipients: Suppose your business repeatedly sends high volume emails to lists of unverified recipients. In that case, the ISP will flag the business domain and IP address used to send the emails as disreputable. Once flagged, the ISP will block all emails from that domain, even to verified recipients. This is a situation that is tough to come back from.

Strategies to improve Deliverability – Verifying Recipients

Use Double Opt-in: A single opt-in is when a website visitor offers a name and email ID, clicks a link, and is automatically added to the email list. Sometimes users misspell their email IDs or offer spurious names and email IDs. When the email ID is added to the email list without verification, emails to this ID are treated as spam.

The impact is worse if the misspelled or spurious email belongs to someone else (of which chances are high) who blocks your emails.

In a Double Opt-in, a request to confirm the intent to subscribe is sent to the offered email ID. It's only after confirmation that the email id is added to the email list. Unconfirmed users remain unverified.

Use Business Email IDs: Many B2B newsletters, or gated resource downloads, require visitors to enter an email ID with a business domain (non-public domain). Businesses impute a seriousness of intent and engagement in visitors offering their official email IDs. Domain names provide another level of insight into visitor profiles, and such email IDS are valuable for future engagement.

Manage Unsubscriptions: The Federal Trade Commission (FTC) makes it mandatory that marketing emails must 1) Clearly tell consumers they can opt out of getting those messages in the future, and 2) Include an unsubscribe link that works.

Users who subscribed earlier sometimes unsubscribe. Some reasons for doing so include a shift in interests, irrelevance, or no longer useful. Whatever the reason, honor them.

Remove unsubscribed email IDs from the mailing list before starting the next email campaign.

Metric - Unsubscribe Rate

The unsubscribe rate indicates the percentage of subscribers who opt out of receiving future emails. Managing a low unsubscribe rate is crucial for retaining a healthy and engaged subscriber base and preserving sender reputation.

A low unsubscribe rate signifies that your email content remains valuable and relevant to your audience, contributing to the sustained success of your campaigns. A low unsubscribe rate improves sender reputation and consequently deliverability.

Metric - List Growth Rate

The list growth rate reflects the rate at which your email subscriber list expands or contracts. A healthy list growth rate indicates that strategies for acquiring new subscribers and maintaining a dynamic, engaged audience are effective.

A positive list growth rate suggests your email campaign attracts new subscribers and retains existing ones.

Track Hard Bounces: Hard bounces are when the ISP passes the email onto the ESP, but the ESP bounces them back for reasons of the email ID being permanently invalid.

Identify all email IDs with hard bounces in your email servers and

• Reach out to the recipient through other channels and request they whitelist your domain into the safe list. Failing which,
• Cleanse your email list of invalid addresses before starting the next set of emails.

Metric - Bounce Rate

The bounce rate reflects the percentage of emails that couldn't be delivered due to invalid email addresses or other issues. A low bounce rate is essential for maintaining sender reputation and inbox placement, as high bounce rates can negatively impact deliverability.

Monitoring bounce rates helps identify and rectify issues promptly, ensuring a clean and updated email list for focused email campaigns.

C. “Email delivered to the Inbox”

A high rate of email delivery, as indicated by your ISP, is not a sufficient condition to measure deliverability. Emails delivered to recipients but flagged as spam either by the recipient of their ESPs, will bypass the Inbox and land in their Spam Folder, but will still show as “delivered”.

So, while your ISP will indicate a high rate of delivery, the measure is ineffective and misleading, because recipients do not get a chance to see them in their Inboxes.

The often misunderstood or overlooked phenomenon is why successful deliverability is defined as “delivered to the Inbox”.

Metric – True Delivery Rate

Real Delivery Rate is Delivery Numbers (Less) Spam Complaint Numbers

Delivery Numbers

Delivery Numbers measure the number of emails delivered to recipients' Inboxes, as reported by the ISP, reduced for the number of emails that bounced.

Spam Complaint Numbers

Spam Complaint Numbers measure the number of recipients who mark your emails as spam.

When users mark an email as spam, ESPs lodge a spam report. ESPs have an arrangement with most ISPs for periodic feedback on the emails that users have marked spam. Since users do not see and engage with these emails, they cannot constitute valid delivery.

High spam complaint rates harm sender reputation and deliverability, underscoring the importance of sending relevant and personalized content.

Real Deliverability: An accurate measure of deliverability is the True Delivery Rate, which is net of Delivery numbers and Spam Complaint numbers, as a percentage of total emails sent.

Minimal spam complaint rates affirm your emails continue to reach the inbox, safeguarding the success of your campaigns. A high True Delivery Rate indicates effective list management and sender reputation, crucial to ensure that your messages reach the intended audience.

Strategies to improve Deliverability – To Recipient Inbox

To improve the deliverability of emails to recipient Inboxes, adopt strategies to prevent your audience from blocking or marking them as spam. If your audience appreciates your emails, their ESP, and consequently, your ISP will not get any spam reports.

Warm Up Your New IP: If you plan to scale your email campaign, especially from new IP addresses, warm up your IPs gradually. Or your ISP will mark them as spam. Or worse, blacklist the domain. This is disastrous for your current and future campaigns looking to use these IPs.

Sending emails through an IP warm-up plan allows your ISP to study and satisfy themselves on your emailing behavior.

Improve Engagement - Personalize the Emails: It annoys recipients to repeatedly get emails they have no interest in. There is a high probability that they label them spam, so it never stays in their Inbox. Apart from being infructuous, it damages sender reputation. Email recipients are less likely to mark emails as spam if they can induce engagement.

Details from a verified subscription, email client, and data on engagement with email contents can be used to optimize email format to the email client and personalize email contents to the specific interests of recipients. This increases the True Delivery Rate and boosts deliverability.

Different degrees of engagement can be measured - starting from opening the email to responding to the CTA and conversion.

Metric - Open Rate

The open rate measures the percentage of delivered emails that recipients open. It provides insights into the effectiveness of your subject lines and email content, reflecting subscriber engagement and interest.

A high open rate indicates compelling content, resonant subject lines, and appropriate email etiquette. It suggests your audience finds value in your emails and increases the likelihood of achieving campaign goals.

Metric -Click-Through Rate (CTR)

CTR calculates the percentage of recipients who clicked on at least one link within the email. A higher CTR indicates your content is engaging and relevant, driving subscribers to take the desired actions. It is also an indication of effective personalization.

A strong CTR signifies that your email content and call-to-action are resonating with your audience, directly contributing to the success of your campaign objectives.

Metric - Conversion Rate

The conversion rate measures the percentage of email recipients who completed the desired action, such as making a purchase or filling out a form. It is a crucial metric for assessing the ultimate success and impact of your email campaigns.

A high conversion rate implies your email content and call-to-action are persuasive and compelling, and leads to desired outcomes that fulfill campaign objectives.

Metric - Email Client Open Rate

This metric provides insights into the email clients subscribers use to open your emails. Understanding them helps optimize email design and format for better compatibility and user experience.

Tailor your emails to the most popular email clients, and affirm your content displays optimally. This will lift the user experience and increase the likelihood of engagement and conversion.

Email Cadence - Create, Commit, and Maintain

Before recipients subscribe to your newsletter, they should know the frequency of the missive. It’s recommended that you mention the periodicity of the missive – daily, weekly, fortnightly, etc. Having committed to a frequency, make sure you have it going out as per schedule. Recipients should know when to expect your newsletter. And anticipate it.

If newsletter subscribers look forward to, and engage with your email, then there is a good chance you are doing everything right.