**Get the webinar replay with BounceX and learn more about why your email reputation matters.

A good reputation is built on trust, and trust takes time to build. In email, without the trust of both the ISPs and your subscribers, you aren’t going to be very successful. So, you might say a GOOD REPUTATION = SUCCESS. In this post, I’ll talk about what it takes to build a good email reputation and how you can maintain it.

What does it mean to have a “good” reputation in email?

Having a good reputation means you are a trusted sender. ISPs know you to be a marketer who follows the rules, and respects their users. Your subscribers know that you are tuned into what they want to receive and when they want it.

Why does your email reputation matter?

Without a good reputation, ISPs won’t trust your mail. That translates to deferrals, spam placement, and even blocks. Let’s face it, if your mail is going to the spam folder or getting blocked, then your subscribers aren’t getting it, and you’re missing out on a lot of revenue.

It’s also important to remember that how your subscribers perceive your mail is crucial. If you aren’t sending them relevant, timely content, then they may complain or unsubscribe. Not only do you lose that subscriber forever, but ISPs are using complaints as a key signal for how trustworthy you are as a sender. See where I’m going with this?

How do you build a good reputation?

A good reputation comes from following best practices, and being tuned-in to your subscribers’ needs. Key drivers at the ISP-level are: complaint rates, percentage of invalid addresses (hard bounces), delete-without-read rates, spam trap hits, and more.

The best way to control those metrics, that the ISPs use to determine your mailing reputation, is to focus on keeping your subscribers engaged and delighted. This involves a lot of data gathering and testing around what your subscribers like. The most important thing to keep in mind is that email is no longer one-size-fits-all. To truly build the trust of your subscribers and be successful, you need to focus on targeted content, rather than the traditional batch-and-blast campaigns that are no longer effective.

How do you maintain your email reputation?

A phrase I often hear associated with email reputation is “It takes a long time to build a good one, and a short amount of time to ruin it.” That couldn’t be more true. Just because you have built a good reputation, doesn’t mean you can sit back and relax! It’s important to stay on top of your program and to continue evolving in a positive way. Just because a subscriber signed up for your mail, doesn’t mean they will always want to receive it. Make sure you are constantly cleaning your list of unengaged subscribers. Ideally, you should try to re-engage those people first! With so many distractions in this digital age, you need to be able to send engaging content to the right people, at the right time. Personalization is key.

Building and maintaining your reputation isn’t easy. Having a reliable sending platform and a great deliverability team are an important component, and SparkPost can help.

Want to learn more about what drives email reputation? Get the replay on why “Email Reputation Matters“.

Clea Moore
SparkPost Deliverability Lead

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How to Use Feedback Loops

For the uninitiated, FBL stands for feedback loop, the mechanism ISPs like Hotmail and Yahoo! use to report spam complaints to senders.

I know this will be totally shocking because, of course, your customers love you, but your messaging programs generate spam complaints if you send commercial email. And while there is a direct correlation between solid deliverability and a healthy response to complaints, I’m not going to drone on about it for another 500 words.

Instead, I’m going to show you how the newly­ released feedback loops module inside 250ok’s Reputation Informant helps you overcome the historical problems preventing senders from getting the most out of FBLs. It enables you to quickly understand complaint trends, pinpoint problem spots, and take immediate corrective action.

feedback loop
See? Problem spots pinpointed.

The key component of thinking about how you respond to complaints is time. Most feedback loops operate in near real-­time, meaning while there can be a delay of days or weeks between the time you send the message and when it is reported as spam, the FBL notification arrives very soon after the recipient files the report.

The only safe way to interpret a spam complaint is to take it as an indication that the recipient wants to opt-
out of that mail stream. Therefore, your responsibility is to do so, immediately.


Repeatedly sending messages to recipients who have opted-­out of those messages is the fastest way to tank your reputation. You can wind up in the spam folder, or worse, be fired by your email service provider for not playing by the rules.

Reputation Informant’s feedback loops module gives insight into several things. It shows your complaint reports over time, the current and historical rates at which you receive complaints, the largest sources by reporting domain, and top sources of complaints broken down by sending IP, subject line, and the sending and receiving addresses.

This visibility enables you to:

  • Understand the campaigns generating the highest complaint rates.
  • ­Identify the recipients hitting report as spam most often.
  • ­Predict which of your IP addresses are likely to be affected and at which ISPs.

You’re also able to drill down and examine the fine details of each complaint event.

Most importantly, the feedback loop module makes it incredibly easy to process opt-­out for complaints by allowing you to export a list of their email addresses. It’s essentially the magic-­unicorn functionality you’ve been seeking in managing your complaints.

feedback loops
Exporting a suppression list will help you opt-out your biggest complainers.

The module’s IP and date­-based filters, along with hour­-level granularity, allow you to examine complaint activity preceding a drop in deliverability at a specific ISP. You can also explore the correlation of your heaviest complaint times with your sending patterns.

Our goal at 250ok is to make every sender look great by empowering them with data and tools that simplify email. By partnering with SparkPost to bring the FBL module to every SparkPost user, we’ve made it easy to understand and effectively respond to spam complaints.

Okay, true. It was also an excellent excuse to create pretty graphs and play with a lot of data. But we swear the main motivation was building great tools for our joint customers. Ahem.


paul headshot

Paul Midgen believes that inside every ruthless revenue-driven sender lurks a recipient-centered Jedi master, and he’s dedicated to setting them free one sender at a time. Before joining 250ok as VP of Engineering, Paul was CEO of Message Bus, ran Inbound Delivery & Anti-Spam at Hotmail, and has spent a lifetime working on things that allow machines to talk to each other for the benefit of humans.



avoiding spam traps

First, a recap of Spam Traps: Part 2. In the last post, I talked about who uses spam traps and how they can impact your mail program. We established that mailing to traps can result in blacklistings and blocks, which limit your ability to reach your active, engaged subscribers. In the final part of this series, we’ll explore avoiding spam traps in the first place, and what to do if they have already made their way into your database.

There are two main reasons that spam traps end up on your list:

  1. Poor address acquisition practices.
  2. Poor list maintenance (commonly known as “hygiene”).

The easiest way to avoid mailing to traps in the first place is to have a well-structured subscription process. This means subscribers are giving clear consent, understand what they will receive, and from whom they will receive it upon sign-up. It goes without saying here, that purchasing a list is a terrible idea. The industry standard best practice is to have the user confirm their subscription, by clicking a link in an email sent to that address. This allows you as the marketer to verify that they entered the correct address, and to be certain they wish to receive your mail. For various reasons, not every program allows for this confirmation process (known as Confirmed Opt-In or COI). So, what can you do to protect your program? Practice good list hygiene.

Good list hygiene means monitoring engagement for all the addresses in your database (via opens and clicks), and regularly removing those who are inactive after a period of time. Guess what? Spam traps will not engage with your mail, so if they made their way onto your list – because a subscriber accidentally or intentionally entered the wrong address when they signed up – you will be removing them through this process. That means that you should start this culling of inactive addresses as soon as possible.

Savvy marketers will have a soft-COI process set up for new users, where they will send a series of welcome emails, which encourage the user to engage with their brand. If the subscriber doesn’t engage with any of these welcome messages, they are automatically unsubscribed from the program. In this case, a spam trap would only receive a small number of messages. In addition to this, but especially for senders who don’t have a soft-COI program, you should be removing subscribers who do not engage after a period of time. That timeframe will depend on your content, mailing frequency, and other program specifics, but a general rule of thumb is 6 months maximum with no engagement. Addresses falling outside that engagement window should be removed from your database on an automated, on-going basis.

Proper list hygiene, combined with a clear opt-in process, will reduce and prevent any negative impact that spam traps might have on your program. But wait! There’s a bonus! These practices are part of a strong foundation for a good sending reputation, so you will also see better delivery and inbox placement at the ISPs. We know that all major ISPs look at user engagement and inactivity as important signals about you as a sender, so why not set yourself up for success?

Okay, now let’s tie all 3 parts together:

  1. Spam traps have no value to you as marketer, because they don’t belong to a real user.
  2. Mailing to spam traps can cause big problems for your program by way of blacklistings and blocks, which stops you from reaching your active subscribers.
  3. Avoiding spam traps in the first place can be accomplished by having a clear, well-structured sign-up process, and maintaining your list regularly based on engagement. This will also result in a better sending reputation and better delivery.

There you have it! Everything you need to know about spam traps.

At SparkPost, we work closely with all of our Elite customers to ensure they are following email best practices, and are successful as a result. Find out more on our product page.

— Clea

Other posts in the Spam Traps series:

  1. Spam Traps Part 1: What Are They?
  2. Spam Traps Part 2: How They Impact Your Mail Program

9 Things ISPs Really Want Email Marketers to Know

Over the years it has become evident that there’s a major disconnect between email senders (email marketers) and ISPs on how engagement is measured. There is not one single engagement metric. In fact, marketers are not privy to the metrics that receivers collect and receivers don’t have access to sender data. Where marketers are interested in opens and clicks, an ISP is more interested in complaints, deletes, and spam designations.

As email marketers it is important for us to understand the positive and negative signals an ISP sees as an engagement. For example, if a recipient moves your email from the spam/junk folder to their Inbox, that’s viewed as a positive signal. But if they delete the message without opening or reading it, that’s considered a negative signal.

ISPs want marketers to understand more than just recognizing positive and negative signals. View the abridged slide show below or download our eBook on 9 Things ISPs Really Want Email Senders to Know.

What ISPs Really Want Email Senders To Know


deliverability_panel_eecI’m in Miami wrapping up #EEC15, The Email Evolution Conference. The closing Keynote Panel Discussion organized by Dennis Dayman and Ryan Phelan was worth the price of admission; the panel they organized featured key postmaster/abuse personal from Comcast, Hotmail/Outlook, AOL and Gmail. Although regular fixtures at M3AAWG meetings, the folks in this room don’t normally have a chance to hear first hand how an ISP measures activity within the inbox and responds to emails as they arrive. There were furrowed brows, heads nodding and a plethora of other emotions as questions were asked, assertions made, accusations levied and laughter enjoyed by all.


One of the most important things I took away from this session and I think you may find this valuable too are the signals that most ISPs read as good vs. bad. Here’s a cheat sheet and take away that you can help you better understand how engagement, which was called ‘a philosophical principle rather than a secret sauce’, is measured by a mailbox provider or an ISP. One of the major disconnects I’ve seen between senders and receivers is the idea that engagement is a single measure. Quite the contrary, senders are not privy to the metrics that receivers are and vice versa, there may be some attribution, analysis through web behavioral data, that leads to a very different picture of engagement on the sender side. This is the fundamental conundrum that I think is best represented by the metric system vs. the english system. Both are valid (well one’s more practical than the other), both are capable of measuring the same distance but use different units. One doesn’t invalidate the other, hence the philosophical nature of the construct.

Positive Signals

  • Open an email
  • Adding a sender to the address book
  • Moving a message to a specific folder (filing)
  • Rescuing a message from the spam folder
  • Replying to a message.

Negative Signals

  • Deleting a message without opening it
  • Marking a message as spam
  • Reporting phishing

Thankfully there are more positive signals that inform engagement at a mailbox provider than negative ones. One thing to consider: I’ve seen a number of senders instruct their recipients not to reply to an email, that the email box will not be checked or monitored. Given that replying to emails is a positive signal that will ultimately improve a sender’s engagement, leading to better reputation and finally deliverability, it might be worthwhile to make the sending addresses accept replies and even review them for customer correspondence.

One of the positive benefits of our annual Message Systems user conference is that we get to sit down and talk with customers, partners and friends in the industry. At the last conference in San Diego back in October, John Arnold from Return Path was nice enough to share his thoughts on the state of the email industry, where we are, how we got here, and where we’re headed. We broke his interview down into a couple of short clips focused on specific subjects.

In the first one John talks about the emerging new standards around deliverability, how ISPs have changed the ways they handle incoming messages and what this means for marketers. For context, the big ISPs such as Yahoo, Google and Microsoft have moved away from trying to block spam based on message content and have adopted acceptance practices that center on sender reputation and recipient behavior – does the message get opened? Is the recipient scrolling and clicking through? John’s explains that, for Return Path, which is the leading provider of email deliverability services in solutions, these shifts in the industry are opening up new opportunities for innovation:

“With a new paradigm of inbox tracking and going through the new benchmarks that we have, such as read rate and all the different data points that come together in that customer’s inbox, there’s going to have to be another industry that grows out of that. So the innovators and the leaders in the space that ReturnPath are working with are seeing this as an opportunity to innovate, to think, to look at all of the different metrics and data points and come up with new benchmarks and charge ahead.”

Watch the second part of the interview on Challenges of Getting Into The Inbox here.

Forrester Research and Marketo join forces to bring you a webinar on the Keys to Deliverability Success! Learn about how you can automate some of the ever present challenges, including the ever changing ISP requirements.

Keys To Deliverability Success Webinar

Adaptive Delivery® (Over) Simplified

We all know that Momentum can deliver email FAST! But, it turns out that Momentum CAN actually deliver too fast and make big ISPs like Gmail, Hotmail, and Yahoo! sort of cranky.

So, another great feature of Momentum (other than speed) is  controlled speed. That is, Momentum can be instructed to deliver email to ISPs in a controlled fashion through Adaptive Delivery (AD).

In order to understand how AD works, we need to have a general understanding of how our customers are able to control HOW Momentum sends messages.

Momentum customers have always been able to manually control how Momentum does the following:

  1. Limit the number of messages sent per hour (or per N seconds)
  2. Limit the number of connections that we’ve established AT ANY ONE TIME
  3. Limit the number of connections that we establish per hour (or per N seconds)
  4. Limit the number of messages we send on ANY ONE CONNECTION

Momentum has so-called “configuration options” that refer directly to these concepts:

  1. Outbound_Throttle_Messages
  2. Max_Outbound_Connections
  3. Outbound_Throttle_Connections
  4. Max_Recipients_Per_Connection

Customers can manually control Momentum’s delivery habits by manually configuring these options in Momentum. It’s important to know that these values can be set with DIFFERENT values depending on:

  1. Which ISP is receiving the message
  2. Which customer (or IP address) is sending the message from Momentum

For example, you might instruct Momentum to limit its interaction with Gmail:

For the domain Gmail.com, never simultaneously open more than 30 connections. In Momentum this might look something like this:

Domain “gmail.com” {

Max_Outbound_Connections = 30


All four configuration options listed above may be manually configured, one at a time, for each ISP, and for each of your sending customers. Here’s the problem with statically setting those: It could be that an ISP “gets upset” with one of your marketing campaigns … perhaps you put some content in the message that was considered “spammy” or you targeted the wrong list and a lot of the recipients tagged the message as “unwanted” or “spam”. All of sudden, the ISP may not want so much mail from you. It’s a real hassle to have to commit the human resources to monitor this all day long, 24/7/365!

Adaptive Comes to the Rescue

With Momentum’s Adaptive Delivery we introduce something pretty cool for the customer: The ability to “send more mail” or “send less mail” throughout the day AUTOMATICALLY based upon the feedback from the ISP. Let’s talk more about that. What do we mean by that?

Mail Exchange (MX) servers are machines that “talk” SMTP (which stands for “Send Mail To People” … or was that “Simple Mail Transfer Protocol”?). When Momentum attempts delivery of a message to a specific ISP, the MX servers let us know the outcome of the attempt through so-called Delivery Status Notifications (DSNs). They roughly come in 3 forms: (These examples are REAL responses from a Gmail MX server):

I’ll take the message! … but Gmail says:

  • 250 2.0.0 OK 1363971536 os3si3214339vcb.23 – gsmtp)

I won’t take it now, but I might take it later … but Gmail says

  • 452-4.2.2 The email account that you tried to reach is over quota. Please direct\r\n452-4.2.2 the recipient to\r\n452 4.2.2 http://support.google.com/mail/bin/answer.py?answer=6558 a1si964185vef.2 – gsmtp
  • 421-4.7.0 [ 10] Our system has detected an unusual rate of\r\n421- 4.7.0 unsolicited mail originating from your IP address. To protect our\r\n421-4.7.0 users from spam, mail sent from your IP address has been temporarily\r\n421-4.7.0 blocked. Please visit http://www.google.com/mail/help/bulk_mail.html\r\n421 4.7.0 to review our Bulk Email Senders Guidelines. s20si1843829vcp.41 – gsmtp

I’m not taking your message (now or ever) – Goodbye! … but Gmail says:

  • o 550-5.1.1 The email account that you tried to reach does not exist. Please try\r\n550-5.1.1 double-checking the recipient’s email address for typos or\r\n550-5.1.1 unnecessary spaces. Learn more at\r\n550 5.1.1 http://support.google.com/mail/bin/answer.py?answer=6596 p8si1427513vdw.10 – gsmtp
  • 550 5.2.1 The email account that you tried to reach is disabled. p19si3057754vcw.43 – gsmtp

How Does Adaptive Work? – A Specific Example

Momentum’s Adaptive Delivery removes a lot of the need for human intervention by adjusting certain traffic shaping options automatically, in real time, while mail is being delivered!

The way that Adaptive does this is through a set of “traffic shaping modification rules” that guides its behavior. Here’s one example of an Adaptive Rule:

[“gmail.com”] = {

responses = {


code = “Our system has detected an unusual rate of.*unsolicited mail originating from your IP address”,

trigger = “1”,

action = {“suspend”, “2 hours”},

message = “IP blocked temporarily due to high complaint rate”,

phase = “connect”,


Now, let’s show what would happen if a Gmail MX server responded to one of our attempts to deliver a given email with the following error message:

421-4.7.0 [ 10] Our system has detected an unusual rate of\r\n421-4.7.0 unsolicited mail originating from your IP address. To protect our\r\n421-4.7.0 users from spam, mail sent from your IP address has been temporarily\r\n421-4.7.0 blocked. Please visit http://www.google.com/mail/help/bulk_mail.html\r\n421 4.7.0 to review our Bulk Email Senders Guidelines. s20si1843829vcp.41 – gsmtp

So What Exactly Happens?

  • Momentum tries to deliver the message
  • Gmail responds with the “421” error message above
  • Adaptive delivery looks at the response from Gmail and consults its “rules file” to see if there’s a match and finds one.

How? The string in the “code” above has a so-called “wildcard match” within it. We will get a match as long as the response from Gmail has these 2 components in it:

  • ” Our system has detected an unusual rate of” AND “unsolicited mail originating from your IP address”
  • Adaptive delivery tells Momentum: Don’t send any more email to Gmail (from a specific sending IP address) for 2 hours.

After 2 hours, Momentum will resume delivery to Gmail, as normal!

What Other Things Can Adaptive Do?

The example above showed how Momentum would stop sending messages to Gmail under a specific circumstance … when Gmail thinks that there is too much unsolicited mail coming from the sender.

However, adaptive can do much more including (but not limited to): reducing connections, reducing the number of messages sent on connections, and warming up IP addresses. I’ll give more information, at a more technical level in my next “Tips and Tricks” article: “Adaptive Delivery (Less Over) Simplified”. Stay tuned!

In this whitepaper, email expert Len Shneyder introduces Message Systems Adaptive Delivery – The first solution of its kind specifically designed to automate the monitoring of bounces and complaints, and adjust connection rates and throughput accordingly. 

Adaptive Delivery Whitepaper

Don’t talk to ISPs about messaging threats. For them, the topic is old hat. Every day, ISPs are bombarded by messaging attacks, and each is one more targeted, more fiendish, more sophisticated than the one before. (more…)

There has been a great deal of talk in the email marketing industry recently about tuning for delivery and effective IP reputation management, but much of it seems to be misguided or misinformed in my opinion. Many of the articles I have read in past months focus on the concept of “getting around” ISP spam filters, or “bypassing” the bulk folder. (more…)