Finding the Right Azure SMTP Relay Service for Your Needs

Over 361 billion emails are sent and received per day. That's over 45 per person on earth. Most of these emails are not exchanged between people but between businesses (and their automated systems) and people, most of which are ignored. But there are some emails that almost no one ignores, like transaction emails when they make a purchase or notification emails reminding them about their appointments.

So business owners need to ensure that these emails reach the intended recipients instead of getting lost in the SPAM folder, and that's where the right Azure SMTP relay service comes into play, at least for businesses that are using the Azure cloud.

Also, choosing the right SMTP relay service for Azure can also ensure that apart from one-on-one emails like notification and transaction alerts, bulk emails (marketing or promotions) also achieve high deliverability rates.

What is an Azure SMTP Relay Service?

Before we take a dive into Azure SMTP relay service, it’s important to clarify the anatomy of an SMTP relay service, starting with SMTP.

SMTP

As the name suggests, SMTP, or Simple Mail Transfer Protocol is a protocol that ensures that an email can be transferred between a sender and a recipient/sender server and the recipient "mailbox." In the context of the internet, a protocol is any standard or standardized method for transferring data online. SMTP is specific to emails, and it protects both ends of a transfer - sender and recipient. For the sender, SMTP ensures that the email is sent to the right/intended recipient, no one else, and for recipients, it ensures that only legitimate and safe emails fall into the inbox. It's not the only protocol that does that, but it's the most widely used one around the world.

Azure supports SMTP as a protocol, but you still need an Azure SMTP relay service (third party) to leverage the relay functionality.

SMTP Relay

SMTP relay is one of the features or functionality associated with the SMTP protocol. SMTP relay naturally kicks in when the email sender and recipient use different servers. The email sent by the sender is relayed from their server to the recipient’s server and then to the end user. But it can also be used as a feature to safely deliver emails and avoid the risk of having your email classified as spam.

One of the ways the spam filters "protect" recipients is by analysing the domain and IP reputation of the sender. If the sender has a good reputation, the email may pass through the spam folder and land in the inbox. If not, or if it's an unknown sender without any reputation, the filters may become suspicious and classify the email as spam.

The SMTP relay can improve an email's reputation by relaying it through servers and IPs with a good reputation, which increases the chances of the email being delivered to the inbox of the recipient.

SMTP Relay Service (Azure or another cloud/server environment)

An SMTP relay service is an email service provider that offers SMTP relay functionality. Even though SMTP relay can also be set up in-house/on-premises servers, it may not have the same success rates when it comes to deliverability as a dedicated SMTP relay service.

The term SMTP relay service is often used interchangeably with smart hosts, and even though they are essentially the same thing, smart hosts often have an additional layer of security in the form of SMTP Authentication.

An SMTP relay service is also often used interchangeably with an Email Service Provider (ESP), but that's usually a mischaracterization. SMTP relay is a singular service, while an ESP may offer a host of other services as well.

Azure SMTP Relay Service

There is no native SMTP relay service in Azure, and Microsoft recommends using "authenticated SMTP relay services…to maintain IP and domain reputation" with Azure VMs or App Service. 

So essentially, an SMTP relay service (Azure) is any third-party SMTP relay service provider that can be integrated with the Azure cloud to send bulk (marketing, promotional, etc.) and one-on-one emails (transactional, notification, etc.). However, with a comprehensive range of SMTP relay service choices available in the market, how do you choose the right one for your business?

Choosing The Right SMTP Relay Service for Azure

The process of selecting the right service for your business when you are using Azure is influenced by several factors. The most significant ones are:

Your Email Needs

You can identify and quantify your email needs by answering a few simple questions:

●     What types of emails do you need to send? Are they bulk emails intended for hundreds, thousands, or more recipients at once? Are they one-on-one automated emails like notifications and transaction alerts? For most businesses, it's usually a mix of multiple email types.

●     How many emails do you have to send in a day, week, or month? That influences the cost of the SMTP relay service for Azure that you choose.

●     The frequency of the emails you need to send.

●     Geography of your target recipients. Not all Azure SMTP relay services may support a global recipient base, and their services might be limited to a few selected regions.

These are the email needs relevant to your choice of the SMTP relay service, but the overall email needs pertaining to your business goals may be far more extensive and influenced by a much larger range of factors.

Types of Emails You Will Send

The types of emails you need to be relayed through the SMTP service may include transactional emails, notification emails, mass marketing emails, etc. It's an important consideration because not all SMTP relay services for Azure may accommodate all these types. Some may be limited to just one type of email, while others may facilitate multiple types.

For some businesses, it’s easier to pick a service that does it all and relays all email types your business may need to send. For others, it’s more feasible to choose the best available relay service for the most important emails they send out (like transactional emails) while choosing the most cost-effective options for other, less demanding types.

Reputation

Make sure you look into the reputation of every SMTP relay service for Azure that you shortlist, especially when it comes to the delivery results for businesses in your industry. Not all services offer equally compelling results for all industries, and if you make a choice based on their positive reviews (as a whole) instead of looking into industry or region-specific success rates, complications, etc., the investment may not pay as well as it should.

Features and Ease of Integration

Not all businesses have access to the same level of IT resources, and many small businesses looking for an SMTP relay service (Azure) may not have adequate in-house resources to integrate the relay service into their Azure cloud/applications or troubleshoot the integration later down the line. So, it's important to look for a service that's easy to integrate and reliable and comes with a healthy support system that you can reach out to for troubleshooting.

Another factor that should impact your choice is the features the SMTP service comes with. This may include an intuitive user interface (UI), real-time delivery reports, and bounce rate stats. However, it’s also important to ensure that you are not paying for bells and whistles and only consider the features relevant to your email and broader business needs.

Cost

The cost of an Azure SMTP relay service may be highly influenced by the amount of emails you need to send in a given time period. Multiple services allow you to leverage the SMTP relay option for a small number of emails for free, but it’s usually impractically low for most decent-sized businesses.

It's also important to analyse the cost in the context of not just the volume but also the ease of use, integrations, and features. Some SMTP relay services may only charge you per the number of emails you send, while others may also take into account the amount of data relayed through the email. A thousand emails with a separate image file for the receipt may be heavier than 2,000 emails with in-text transaction receipts.

It’s worth noting that for many email service providers, SMTP relay is simply a feature rolled into the pricing packages and is not a significant enough cost factor by itself.

Azure Compatibility

Azure compatibility is one of the most important technical considerations when it comes to the right Azure SMTP relay service. There are two easy ways to find SMTP relay services that are compatible with Azure and can easily be integrated.

The first is to look for these services in Microsoft Store. There are a handful of choices there, but they are quite easy to integrate into your Azure apps/VMs/environment.

The second is to look for the best relay services based on your email needs and look into their Azure compatibility.

Note that it's one of the factors that may change over time. Some SMTP relay service providers may stop supporting Azure Cloud. One example is MailJet, which can no longer be used in conjunction with Azure apps/VMs, even though it was one of the popular SMTP relay choices in the past.

SMTP Relay Service (Azure) Choices To Consider

Three Azure SMTP relay services that may be the “right” one for your business are:

Maileroo - Best For Transaction Emails (and Pricing)

If you are looking for an SMTP relay service (Azure) designed specifically for transaction emails, Maileroo may be the best option, hands down. But even though it's geared towards transactional emails, it offers useful features like a dedicated IP for businesses with high-volume email needs (over a million emails a month) and an intuitive dashboard that allows you to track email open rates, clicks and bounces in real-time.

It also offers highly competitive pricing. The standard plan for 25,000 emails a month is available at just $15.00, while the enterprise plan for a million monthly emails costs $400 (including one dedicated IP). There is also a free pricing plan for businesses that only send out a thousand emails a month.

SendGrid - Best Overall

SendGrid is a Microsoft Azure partner and is endorsed by the tech giant as an authentic SMTP relay service for Azure. It's also available through the Microsoft Store, and there are multiple resources on the Microsoft website dedicated to the integration and troubleshooting of SendGrid on Azure.

Scalability and its focus on deliverability are just two of the reasons SendGrid stands out, not just as an SMTP relay service but as an email service partner. It also offers a generous free version, with 2,000 emails per month (for marketers). Other than that, it just has two pricing tiers, which go from $15 to about $200 a month for a maximum of 300,000 emails. The advanced tier costs about $900 a month for up to 950,000 emails per month.

SocketLabs - Best Free Trial

SocketLabs is another SMTP relay service available on the Microsoft Store. It's well regarded for its easy integration and comprehensive reporting that takes into account over 35 data points and allows you to make data-driven decisions. It also offers an IP allow-listing feature that benefits senders with new email addresses/domains.

SocketLabs offers a 30-day free trial for their core pricing tier, which allows businesses to send about 40,000 emails in a month. The core tier costs about $39.95 a month. The other two tiers are pro and enterprise, which come with a custom price plan. The pro tier may cost between $79.95 and $425 for 100,000 to 800,000 emails, though it also includes a dedicated IP, which is usually reserved for enterprise plans.

Final Word

Choosing the right Azure SMTP relay service is more than just a technical decision and must be considered after evaluating your business’s email needs and available resources. Choosing a bulky solution that may overfit these needs will not just be costly, but it may also lead to operational friction and delays. 

For businesses that are looking for an SMTP relay service for Azure for their transactional emails, Maileroo may prove to be a perfect fit, but if your email needs are more broad-scope, you may consider looking into other options, like SendGrid or SocketLabs.