Commercial Emails and Transactional Emails: Differentiators and Best Practices

Whether you’re sending commercial or transactional emails, making sure your message gets where it’s going, gets read and makes an impression is of the highest priority. What’s the difference? Transactional emails are sent to a person as a result of a specific action taken by the user. Commercial emails are promotional emails sent to a user in order to drive awareness, encourage engagement, or make a sale.

By following a few simple best practices you can ensure both your commercial and transactional emails hit their targets and stay out of the spam folder.

transactional emails infographic


Microsoft Hotmail Outlook Deliverability Inbox


The Microsoft Outlook inbox is one of the major destinations for most email senders, especially those with large numbers of consumer subscribers. It also has a reputation for being somewhat tricky to get into. Here’s what senders need to know to get the best Hotmail/Outlook deliverability and ensure their messages reach the inbox.

Microsoft’s Outlook service—whether known by the brands Hotmail, Windows Live, MSN, or—uses a combination of factors to determine whether to treat a message as credible or as spam. Like all ISPs, Microsoft’s methods are proprietary. But we know that it analyzes signals that include content, authentication, and domain and IP reputation to create a “trustworthiness” score. Less-than-optimum scores can cause your messages to be “delayed” and/or “spam filtered.”

Best Practices for Hotmail/Outlook Deliverability

Here are six best practices to help maximize Microsoft Outlook deliverability:

1. Warm Up New IPs – Microsoft will only allow 10,000 messages per day for new IP addresses. It will delay the remainder of messages sent from new IPs. Delays are normal when developing an IP reputation.  As your reputation develops over a 2–4 week probationary period, the delays will lessen and eventually discontinue.  The volume of messages that are delivered successfully on the first attempt will rise as Microsoft moves you to a higher reputation level.

Best Practices: to avoid delays, start with 2,000 traffic to Outlook/Hotmail, double every day until you see “RP-001 (DYNAMIC CODE) Unfortunately, some messages from a.b.c.d weren’t sent. Please try again. We have limits for how many messages can be sent per hour and per day. You can also refer to” then slow down the traffic until these delays discontinue.” Note: We highly encourage senders to use their own “custom bounce domain”, “tracking domain” and “dkim sign” with their own domain.

2. Listen and Respond to FBL Complaints – It is important to honor any unsubscribe requests whether a subscriber hits the spam button or the unsubscribe link.  Continuing to send to subscribers that have unsubscribed will harm your reputation with Microsoft. SparkPost applies for and processes Feedback Loop (FBL) complaint feedback for you to minimize this risk.

Best Practices: Add text reminding subscribers where they opted-in to receive your message.  Ensure your messages are relevant and sending at a frequency that the subscriber is expecting.  Remove subscribers that do not engage with your messages.  If as little as 0.5% of your subscribers complain, it will affect your ability to send to your entire subscriber base.

3. Minimize “Unknown User” Hard Bounces – Do you practice positive list hygiene?  Are you sending to an old list that includes a large number of inactive or dead addresses?  Microsoft sees this as a sign of email harvesting or spamming.

Best Practices: Practice list hygiene by maintaining your list.  Purge addresses that have been inactive for 12 months, change the frequency to addresses 3 to 6 months old.  Consistently attempt to re-engage subscribers using different tactics.  Normal unknown user rates average less than 2 to 3 percent.

4. Avoid Spam Trap Addresses – Addresses used by ISPs and law enforcement agencies to identify email harvesting/spammers.

Best Practices: Maintain list hygiene with hard and soft bounces. Bounce notices can provide invaluable information about how Outlook (or any provider) is treating your messages. It is critically important that you keep spam trap rates below 0.01% to avoid reputation issues.

5. Properly Configure Your Sending Infrastructure and Content – Microsoft looks for well set up infrastructure and aligned content as an indicator of a good sender. Microsoft also applies a proprietary content filter called SmartScreen. SmartScreen learns from data provided regarding known phishing threats as well as from Microsoft customers to determine what characterizes good mail and unwelcome mail. Filtering is accomplished by probability-based algorithms used to distinguish between legitimate e-mail and spam.

Best Practices: Always use valid, reputable URLs. Avoid using IP addresses in the URL. Publish your Sender Policy Framework (SPF) records. Focus on content, as well as URLs and HTML elements.

6. Sending Frequency and Consistency – Sending from the same IP address(es) with consistent volumes and frequencies month over month is ideal. Spammers tend to “pop up” on an IP and disappear. Infrequent senders who send large volumes once a month or quarterly can be an indicator of a spammer or a compromised server.

Best Practices: Be consistent.  Segment your sends. Prioritize sending genuinely wanted content to a smaller number of engaged subscribers over sending generic content to your entire list. Include your call to action early in your content so subscribers will see it quickly as they scan your message.  Avoid link shorteners like and align your links with your content.  Personalize your content to your subscribers’ interest.  Don’t send the same content to your entire list, but instead but segment and personalize using dynamic content.

The Golden Rule for Hotmail/Outlook Deliverability

Overall, Microsoft has incorporated content filtering with authentication and reputation for a combined “trustworthy” score with which it determines how to handle messages and determine Hotmail/Outlook deliverability.  So the simple answer is to follow best practices consistently. Send to only subscribers the content that they expect, when they expect it. That’s the golden rule of email deliverability to Outlook or any ISP.

For more information about Hotmail/Outlook deliverability straight from the source, visit the Microsoft postmaster page.


10 Steps Great Deliverability Blog Footer


You really can’t say enough about transactional email! These bread-and-butter messages are some of the most powerful emails you can send. The headline on our recent Infographic tells you why: “Received, Read and Remembered.”

My blog post “The Anatomy of Good Transactional Email” dissected emails that took everyday transaction messages from “okay” to “incredible.” How? They considered the key elements of each message and revamped them to make them more meaningful and valuable to their recipients. (Go ahead and check out that post first if you want. I’ll wait.)

You can do this, too. A little thought, a little copywriting, some branding strategy, and boom – you’re on your way to creating a stronger relationship with your customers than you would get with a plain old “thanks for subscribing” or “your package is on its way” email.

I can hear you now: “This all sounds great, but seriously, how do I get started?” Right off the bat, I can think of three transactional emails you’re probably sending already but not building up for maximum potential:

  1. welcome or on-boarding email series to new customers, clients, members or accountholders.
  2. An abandoned-process email series (or “abandoned-cart”) to customers who exit your site without finishing what they started – purchases, downloads, account registrations, payments, forms or whatever. (Granted that you know whom they are when they come to your site).
  3. post-transaction email series that sends relevant, information-based messages following a successful transaction—think reviews, similar products, surveys about the entire purchase and shipping process.

These three represent three key points of your customer lifecycle. But did you see what I did there? I’m not talking just about beefing up one email and letting it go. Just as one purchase does not a loyal customer make, one email isn’t going to build an entire relationship bridge to that customer. Upgrading a single, simple transactional email into a value-added series gives you more opportunities to build brand trust, remove FUD (fear, uncertainty and doubt), encourage repeat transactions and extend the relationship.

Why three emails? It’s not a hard and fast number. But, three messages, strategically spaced, will deliver key information without making them feel hounded and give them more opportunities to take the actions you want. I’ll talk about the welcome/on-boarding process here and cover the other two in a future blog post. So, stay tuned.

Warming up your newbies with an on-boarding program

A welcome/on-boarding program lets them knew they engaged successfully and builds trust in your brand. It’s also a way to stand out from your top competitors. A 2015 Return Path study found 75 of the top 100 Internet Retailer brands send welcome messages. But, only three of those 75 companies send a series. An email series is a good way to get people hooked on your email. People who read three emails in a welcome or on-boarding program will go on to read 69% of that brand’s emails over the next six months according to the same study.

The content in your welcome email series will depend on what best serves subscriber needs and your business goals. Look at your business model. What must your customers do to get full value from your products or services, and which actions drive your business?

Below are some suggestions:

  • Confirmation of transaction details (email address used, name, account details, etc.)
  • Instructions for taking the next step (creating or logging into an account, filling out preferences, completing the next transaction, etc., connecting other accounts, etc.)
  • Sign-up incentives or bonuses
  • Links to customer support, FAQs, video how-tos or troubleshooting info
  • Invitation to join a loyalty program or to connect on social media
  • Links to interesting or helpful places on your website
  • Mobile app links and download instructions

By the end of the series, you’ve moved beyond the initial transactional email and warmed up your customers to receive your promotional emails. That’s better than dropping them into the fire hose of your promotional email program.

Testing can show you which information combinations get the most clicks and conversions, and whether you should list them in the beginning, middle or end of the series.

Welcome email best practices:

  • Send the first email as soon as possible. The longer you wait, the less likely your customers will be receptive, remember, out of sight, out of mind!
  • Use layout, navigation and brand elements that reflect your regular emails.
  • Limit the scope of your emails and ensure the content is closely related to the recent transaction or customer interaction to ensure maximum relevancy.
  • Track activity (opens, clicks and conversions) on each email. Watch for customers who don’t open or who drop off during the series. Segment them for early-intervention messages, such emails that restate your brand value or USP.










opt-in formYou should always get your recipients’ permission to email them anything other than transactional messages (such as receipts). But how you ask for permission can make a big difference in how many people sign up for your mailing list. Beyond how many people sign up, a good opt-in form can help you gain subscribers who will be more engaged and help you get better deliverability over time. This post will discuss a few best practices for optimizing your opt-in forms.

Clear Branding

Branding on your opt-in page should tie back to the messages your recipients will receive. Use fonts, colors and logos that you will use in your emails. If you are a parent company for multiple brands, you may wish to have separate opt-in forms for each brand, or to use each brand’s logo next to the checkbox to opt in to that particular brand’s mailing list. Your goal is for someone to recognize your message in their inbox as something they signed up for and want.

Set Expectations

Most people don’t expect to hear from a B2B software company every day, but they’d worry if they didn’t hear from a daily deals site on a daily basis. Letting your recipients know approximately how often they can expect to hear from you will help them make an informed choice to join your list. One of the top reasons people click the spam button on messages they actually signed up for is that they receive too much mail from the brand in question. If recipients know what to expect, you can prevent problems ahead of time.

Include an Unsubscribe Statement

The U.S. CAN-SPAM act and Canada’s Anti-Spam Law (CASL) both require that senders include an unsubscribe statement in all emails. In other words, your form or the introduction to your form should include a statement to the effect that users can unsubscribe from your mailings at any time.

Include Your Address

Under CASL, senders must include their physical mailing address on pages that collect email opt-in. You can (and should) include this information on the site footer and not as part of your opt-in form, but it’s important not to forget it.

Separate Your Opt-In

Studies show that the more form fields you ask someone to fill out, the fewer people fill them out. While you might want a lot of information from your subscribers, it’s best to ask for that information after you have obtained their email consent. This will help maximize your opt-ins, and allow you to ask for additional data later, as you continue to build a trusting relationship with your subscribers.

Additionally, it is illegal in Canada under CASL to bundle email opt-in with making a purchase or generally agreeing to terms and conditions. Canada requires that you use a separate check box for email opt-in, and checkboxes may not be pre-checked. While this isn’t a legal requirement in the U.S., it’s still a good practice as a means of ensuring your recipients are clearly aware that they can expect to receive emails from you.

Confirmed Opt-In

Sometimes called “double opt-in,” confirmed opt-in is when you send a confirmation message to someone who has filled out your opt-in form; they must then click a confirmation link in order to fully join the list. Some organizations shy away from using confirmed opt-in in the fear that this will reduce their subscribers, but studies show that subscribers who persist through the confirmation process are significantly more engaged and more likely to click your links.

Not only are confirmed opt-in subscribers more engaged, they also are not spam traps. People sometimes enter false email addresses into forms in an attempt to get to a download without providing their real email address. Sometimes these email addresses belong to other people (who then report your messages as spam, since they did not opt-in), and sometimes they happen to be spam traps (which can result in blacklisting and other deliverability problems). Using confirmed opt-in helps protect you from these problems so you are better able to deliver messages to your engaged recipients.

Log Opt-In Data

It is important to have an auditable data trail for opt-ins. This information is legally required for Canadian recipients under CASL, but it’s also a good idea to have this information if you ever receive spam complaints to your email service provider or domain registrar. If you can easily show your data, these types of complaints are easy to resolve quickly and without impact. On the other hand, if a governmental agency or the abuse team at a service provider is concerned about your sending practices and you don’t have this information, you could wind up with service disruptions or fines for non-compliance. It’s best to maintain this data as a means of protecting yourself from liability.

What data should you keep for an audit?

  • User IP address
  • Timestamp of opt-in
  • URL of opt-in form
  • Copy of the form itself (make sure to archive older versions every time you make a change to your form!)

There are endless ways to design and manage opt-in forms, but following these basic guidelines will go a long way to helping your email programs perform better over time.