Email marketing is one of the most effective tactics for driving sales and generating new leads. Your success depends on your ability to reach your customer’s inbox. Once you hit send, your emails go through multiple testing paths. The better your reputation as a sender, the more emails get delivered into the inbox.

Managing your sender reputation is vital to ensuring your messages are delivered reliably. Email deliverability is an issue faced by many companies depending on email to send important messages to their customers. Over 20% of acceptable emails, including email & shipping confirmations and password resets never reach the recipient’s inbox.

Let us look at some important factors driving sender reputation:


Complaints occur when the subscriber marks an email as spam or moves it into their junk folder. A high complaint rate can block your emails and can cause a bad sending reputation. It is calculated by dividing the number of complaints by the number of delivered messages.

How to reduce your complaint rate?

  • Stick to the type of content for which your subscribers have opted in.
  • Target your subscribers based on their interests. They are likely to unsubscribe if your email doesn’t bring any value to them.
  • Send emails at a right frequency, as forgetful customers tend to unsubscribe more.
  • Check your acquisition and permission practices for opting in your customers.
  • Make the unsubscribe process easier so as to avoid complaints.

A few complaints will not harm your reputation as it may just be some lazy unsubscribes. It is better to keep these complaints below a threshold. For example, Return Path provides comparative data to the ISPs to decide the acceptable limit for complaints.


Unknown Users

Sending your marketing emails to non-existing users makes no sense and also adds to bounce rate. An unknown user is generated when you send mail to a recipient that never existed, inactive users or an address abandoned by the subscriber. Check your email list regularly for misspelled, inactive email addresses to filter out all inactive users. You can also find unknown users by identifying the SMTP error codes. Keep this rate to a minimum to build sender credibility.

How to avoid it?

  • Remove the hard bounces from your list and regularly monitor the soft bounces.
  • Review your email collection process and ask users to confirm their email address.
  • Monitor the feedback loops and analyze the SMTP error logs. Major ISPs provide feedback loops, in which the sender can gain information from the recipients who have complained about that sender’s email.

Spam Traps

These are the email addresses which are specifically created for the purpose of finding spammers. These should not be found on any of your opt-in lists. Hotmail postmaster Travis Wetherbee describes a spam trap as “one of the most widely exploited fraud management tools utilized by Internet Service Providers (ISPs).”

There are two primary types of spam traps employed by ISPs that have an impact on sender score reputation: Pure spam traps and Recycled spam traps. Pure spam traps are the addresses created for the sole purpose of catching spammers. They have never been used as an active email address and can create deliverability issues. Recycled spam traps are the email addresses that were once owned by individuals. After a period of inactivity, the ISP will turn the account off and return hard bounce or SMTP errors. Some addresses are reactivated by ISPs for spam traps.

How can you avoid spam traps?

  • Do not purchase email lists.
  • Remove disengaged subscribers – monitor email addresses that become inactive.
  • Avoid sending messages to role accounts (i.e.,
  • Efficiently remove hard bounces and utilize suppression lists for every campaign.

Volume of Email Sent

Volume is another factor in improving sender score. According to Return Path, “Volume refers to the numbers of emails seen by the reputation network over the past seven days and it focus on sending patterns, consistency, and cadence.” Hence, you should avoid the unusual spikes in your email traffic. For example, if an IP address sends 1 million emails every month and all of a sudden the number increases to 12 million, it can hurt your sender reputation.

Is reputation tied to your sending IP address or your domain?

Presently, most ISPs are using IP addresses, but in the near future it may shift to an IP/domain pairing to determine reputation. Authentication will help ISPs assign reputations more precisely, by tying this reputation to both sender IP addresses and sender domains.

Email marketing can do wonders to your business only when those emails are delivered. Your sending reputation is the main element in getting high inbox placement rates.


by Benchmark Team