Email Infrastructure: The Backbone of Email Marketing
If you want to make money from your email list, it’s vital your messages reach your subscribers’ inboxes. To do this, you need good email infrastructure.
In this comprehensive guide, we’ll discuss email infrastructure, its various components, how it affects your email marketing efforts, and how you can choose an email platform with robust infrastructure.
What is Email Infrastructure?
In email marketing, email infrastructure refers to the technical components and systems needed to send, manage, and optimize email campaigns effectively. It consists of elements such as email servers, protocols, mail agents, and more (detailed information below).
In addition to these components, infrastructure also involves various security measures, compliance considerations, and scalability requirements to ensure reliable and effective email delivery.
A well-built email infrastructure should be a priority for all email marketers as it ensures deliverability and compliance, plus allows for scalability. Dependable infrastructure helps your emails reach inboxes without being flagged as spam.
Let’s review all the reasons why it’s so critical in email marketing.
Why Robust Email Infrastructure is Critical for Email Marketing
Email infrastructure plays an essential role in the 9 aspects of email marketing mentioned here.
1. Email Deliverability
Solid email infrastructure ensures emails reach recipients’ inboxes instead of being flagged as spam — aka email deliverability. Proper email authentication builds trust with ISPs and protects your sending reputation.
2. Sender Reputation
You need to use high-quality email infrastructure if you want a good email sender reputation. Using reputed IPs, configuring DNS records, and managing bounce rates help maintain a positive sender reputation. This translates to better deliverability and higher engagement rates.
3. Email Volume
If you’re a high-volume sender and want to see good email delivery rates, email infrastructure is vital. Robust infrastructure allows you to send thousands of emails at once without performance bottlenecks or system crashes.
4. Phishing Attacks
Using dependable email infrastructure means good authentication is in place; this prevents unauthorized use of your domain, safeguarding your brand and recipients from phishing emails.
5. CAN-SPAM and GDPR Compliance
Proper infrastructure ensures compliance with laws such as GDPR and CAN-SPAM by managing opt-ins, opt-outs, and consent records, avoiding legal penalties.
6. Email Campaign Metrics
A strong infrastructure allows for reliable tracking of email open rates, click-through rates, bounce rates, and other performance metrics, enabling data-driven decisions for optimizing campaigns.
7. Email Performance
Emails sent via well-established infrastructure tend to experience higher engagement rates (opens and clicks), as they are delivered promptly and reliably to the intended recipients.
8. Feedback Loops
Integration with feedback loops allows marketers to manage spam complaints effectively, reducing the risk of being blacklisted.
9. Email Marketing Costs
By minimizing bounces, spam complaints, and legal risks, a strong infrastructure reduces email marketing costs associated with poor deliverability and potential fines for non-compliance.
The Building Blocks of Email Infrastructure
The different components of email infrastructure work together to ensure email communication functions as intended.
These 6 components work as a team to deliver your campaigns:
- IP addresses,
- Mail agents,
- Email domain,
- Email servers,
- Email protocols,
- Feedback loops.
You can find more information on each below.
IP Address
An email IP address in email marketing is the unique identifier for the server used to send emails.
For email marketers, there are two types of IP addresses to consider:
- Shared IP Address: A shared IP is used by multiple senders. It’s more cost-effective, but your sending reputation is tied to the actions of others using the same IP. If another sender abuses the IP, it could negatively affect your email deliverability.
- Dedicated IP Address: A dedicated IP is exclusively used by one sender. It gives more control over your sending reputation and is ideal for high-volume senders. However, a dedicated IP needs to be “warmed up” by gradually increasing email volume.
The reputation of your IP address is crucial to deliverability. If mail services suspect you’re a spam email sender because of emails from your IP, future messages could be sent to spam folders.
Mail Agents
Mail agents refer to the different software components that handle various stages of the email lifecycle, from creation to delivery. The interaction of these agents ensures the smooth sending and receiving of emails. A robust setup minimizes delays and delivery issues.
Mail agents fall under the following 4 types:
| Mail Agent | How they work |
|---|---|
| MUA (Mail User Agent) | This is the email client or interface that a user interacts with to read, compose, and send emails. It interacts with the MTA to transmit messages. |
| MSA (Mail Submission Agent) | This agent receives outgoing mail from the MUA and sends it to the appropriate MTA. It ensures that the outgoing email is formatted properly and ready for transit. |
| MTA (Mail Transfer Agent) | The MTA is responsible for the actual transmission of emails between servers. It routes the email from the sender’s domain to the recipient’s domain, handling the delivery process. |
| MDA (Mail Delivery Agent) | Once the email reaches its destination domain, the MDA receives it and places it in the recipient’s inbox or spam folder. The MDA works with filters to route emails based on specific criteria. |
Further below, we explain the role they plan in transporting emails.
Email Domain
An email domain is the part of the email address after the “@” symbol (for example, campaignrefinery.com). Using a custom domain, rather than a generic one (like Gmail or Yahoo), is essential for branding and trust in email marketing.
Email marketers must follow a schedule to check domain reputation. This helps catch issues early on.
Email Servers and Protocols
The email server sends, receives, and stores email messages, functioning as a digital post office. It handles the delivery and management of all emails.
For its tasks, it uses these three protocols:
| Email Protocols | How they function |
|---|---|
| SMTP (Simple Mail Transfer Protocol) | This protocol is used for sending emails. It transmits messages from an email client to an email server. SMTP ensures emails are routed properly but does not handle incoming emails. |
| IMAP (Internet Message Access Protocol) | IMAP is used to receive emails. It allows users to access their email from multiple devices, as emails are stored on the server and not downloaded to the device. |
| POP3 (Post Office Protocol version 3) | POP3 is also used for receiving emails, but unlike IMAP, POP3 downloads emails from the server to the local device and typically deletes them from the server afterward. |
Email Authentication Protocols
Email authentication protocols are mechanisms used to verify the sender’s identity and prevent email spoofing. They help ensure emails are sent from legitimate sources and reduce the risk of spam, phishing, and other email-related threats.
The three main email protocols are:
| Email authentication protocol | Full name | Its role in email security |
|---|---|---|
| DKIM | Sender Policy Framework | SPF verifies whether the message was sent from an authorized IP address of the email domain. |
| DMARC | DomainKeys Identified Mail | DKIM confirms that the email content has not been altered and is from its claimed domain. |
| DMARC | Domain-based Message Authentication, Reporting & Conformance | DMARC aligns SPF and DKIM with the “From” address and provides policies for failure-handling. |
Prominent mailbox providers like Gmail and Yahoo recently released a spam update where they laid down guidelines for all bulk email senders. A key requirement is the implementation of authentication protocols.
Besides these email security protocols, it’s equally critical to use SSL in email; alternate methods can cause problems with deliverability.
Feedback Loops
Feedback Loops (FBLs) are a service offered by major mailbox providers (or ISPs) such as Gmail and Yahoo to notify email senders when a recipient marks one of their emails as spam. These notifications give the sender insight into how their emails are being received and allow them to take corrective actions.
Major ISPs require senders to sign up for feedback loops to receive these notifications.
Next, let’s examine what happens once you send an email campaign.
How Messages Travel Through Email Infrastructure
If you’re curious to learn how an email interacts with various components of email infra as it travels from your computer to your subscribers, this section has the answers.
When an email marketer sends an email campaign, it triggers a series of interactions within the email infrastructure to ensure the message reaches its intended recipients. Below is the step-by-step breakdown of what happens.
Step 1: Email Creation in the MUA
The marketer creates the email using an Email Service Provider (ESP) or an email client (or MUA). The email content, including the email subject line, body, images, and recipient list, is finalized and queued for sending.
Step 2: Sending Process via the MSA
Once the email is ready to send, the MSA receives the email from the MUA. The MSA checks if it has the correct sender, recipient information, and follows the proper email format.
If any problems occur at this stage, the MSA may return the email to the sender for corrections.
Step 3: Authentication and DNS Checks
Before the email is dispatched to recipients, various authentication protocols are checked through DNS email records, ensuring the email’s legitimacy.
This step is crucial because without these DNS records, the email may be flagged as spam, or rejected by the recipient’s server altogether.
Step 4: Email Routing via the MTA
The MTA is responsible for routing the email to its destination. It takes the email from the sender’s domain and identifies the recipient’s domain (for example: travis@campaignrefinery.com). The MTA looks up the recipient’s domain’s MX records in the DNS, which provides the IP address of the recipient’s mail server.
The MTA transmits the email to the recipient’s MTA via SMTP. This involves a series of back-and-forth communications between MTAs to ensure the email is properly transmitted.
Step 5: Receiving the Email via MDA
Once the email reaches the recipient’s domain, the receiving MTA hands it off to the MDA. The MDA runs a reverse DNS lookup and then places the email into the appropriate folder. This is typically the inbox, but it could also be routed to the spam or junk folder based on filters.
The filtering rules are based on spam scoring, sender reputation, or recipient preferences.
Step 6: Interaction with the IP Address
Throughout this process, the IP address of the sender’s server plays a critical role. If the marketer is using a dedicated IP address, the email deliverability is influenced solely by that sender’s history and reputation. A clean, warmed-up IP address will have better deliverability.
If the marketer is using a shared IP address, the reputation is shared with others using the same IP. Poor sending practices by others — such as sending spam — can negatively impact deliverability for all users on that shared IP.
Major ISPs and email services, like Gmail or Outlook, monitor IP addresses closely. A bad reputation can lead to messages being sent to the spam folder or outright rejected.
Step 7: Recipient Interaction and Feedback Loops
Once the email lands in the recipient’s inbox, the recipient can interact with it. They might open it, click on links, or ignore it altogether.
If the recipient marks the email as spam, it triggers the Feedback Loop mechanism. Email marketers should monitor these feedback loops to ensure they are not sending unwanted emails.
Types of Email Infrastructure Solutions
Email marketers or businesses can choose 4 methods to set up email infrastructure:
| Email infrastructure type | What is it? |
|---|---|
| Open-source | This refers to self-hosted infrastructure using open-source Mail Transfer Agents (MTAs) such as Postfix or Exim. |
| Licensed | This refers to software and hardware installed and managed on-premises for email delivery, such as PowerMTA or MailerQ. |
| Cloud-based | This option involves email delivery infrastructure hosted in the cloud by providers such as Amazon SES or Campaign Refinery. |
| Hybrid | This model combines on-premise MTAs with cloud-based sending services for flexibility and redundancy. |
Using Email Infrastructure Correctly: 6 Best Practices
Follow these 6 steps to ensure you optimally use your infrastructure.
1. Warm Up Your IP Address and Email Domain
When sending emails from a new or dormant IP address or email domain, it’s crucial to “warm up” both gradually to build a positive sender reputation. Sending a large volume of emails immediately can result in ISPs flagging your emails as spam due to the sudden activity spike.
You need both IP and domain warming:
- IP Warming: Start by sending a small number of emails (to your most engaged users) and gradually increase the volume over several days or weeks. This controlled sending allows ISPs to recognize your IP as a legitimate sender.
- Domain Warm-Up: Similarly, if using a new domain for email campaigns, warm it up by sending smaller campaigns at first. Gradually increase sending volume while maintaining high engagement to demonstrate credibility to ISPs.
By warming up both, you ensure a solid sender reputation from the outset. Continue to run email deliverability tests to track results.
2. Respect Feedback Loops
Feedback loops are essential for monitoring how recipients interact with your emails, specifically when they mark your emails as spam. Major ISPs like Gmail, Yahoo, and Microsoft offer feedback loops that notify you of such actions.
Subscribe to each ISP’s FBL service; once subscribed, you’ll receive notifications every time a recipient marks your email as spam. If that happens, remove them from your list. Ensure you follow email unsubscribe laws.
3. Use a Professional Email Address
Using a professional email address that matches your domain (travis@campaignrefinery.com) is key to building trust with both recipients and ISPs. Avoid free email services like Gmail, Yahoo, or Hotmail for sending marketing emails.
A professional email address, combined with proper authentication, signals to ISPs that you are a legitimate sender and helps with email branding, too.
4. Send High-Volume Emails in Batches
Sending large volumes of emails all at once can trigger spam filters and lead to queued emails. ISPs closely monitor sending behavior — sudden spikes in volume can be seen as suspicious activity. If your ESP seems slow and you’re wondering how long it takes for emails to send, this is the reason.
To avoid overwhelming mail servers, you should:
- Segment your email list,
- Send in smaller batches over time.
When you send in batches, monitor the results of each batch and address any issues — such as email bounce rates or spam complaints — before sending the next batch. This approach allows for more control over your email performance.
5. Monitor Blacklists
Blacklists are databases that track IP addresses and domains associated with spammy behavior. If your IP address or domain ends up on a blacklist, your emails will likely be blocked or sent to spam folders. Regularly monitoring blacklists is essential for maintaining high deliverability rates.
Use tools like MXToolbox or MultiRBL to regularly check whether your IP address or domain is on any blacklists. If you find yourself on a blacklist, take immediate steps to resolve the issue.
6. Keep an Eye on Sender Reputation
Your sender reputation is a score assigned by ISPs that reflects the trustworthiness of your email-sending behavior. A good sender reputation leads to better inbox placement, while a poor one results in emails landing in spam. If you have to keep asking subscribers to add your email to a safe sender list, the root cause could be a low sender score.
Services like Google Postmaster Tools and Microsoft SNDS provide insights into your sender reputation.
To maintain a good reputation, avoid using spammy language, maintain email list hygiene, manage bounces effectively.
What Email Infrastructure Should an Email Marketing Platform Offer?
A good ESP will offer robust email deliverability services. Consider the factors below when choosing an ESP.
- Deliverability: A well-configured infrastructure ensures emails reach the intended recipients, minimizing spam and bounce rates.
- Scalability: It handles large volumes of emails comfortably, especially during peak hours.
- Reliability: A robust infrastructure minimizes downtime and disruptions to email communication.
- Security: It helps protect against email-related threats such as phishing and malware.
- Dependable data: By tracking key metrics, trustworthy email infrastructure enables you to make data-driven decisions and optimize marketing efforts.
- Help with compliance: Email infrastructure should help you comply with specific regulations, such as GDPR or CAN-SPAM.
Campaign Refinery: Cutting-Edge Infrastructure and Practices
When we started out, we had a vision — we wanted Campaign Refinery to be the kind of platform where email marketing veterans would feel right at home. While infrastructure plays a big role, an equally big part is played by best practices.
Campaign Refinery implements both in perfect harmony.
Our robust email infrastructure ensures seamless delivery and optimal performance. With state-of-the-art technology and a commitment to best practices, we maintain a strong sender reputation and minimize spam rates. We are constantly fine-tuning our systems to monitor and optimize email delivery, ensuring your messages reach their intended recipients.
All these efforts have paid off; Campaign Refinery offers you the best email deliverability on the market.
Why wait? Unlock your best email performance yet — apply here to become a Campaign Refinery sender!
