Email Sender Reputation 101

Jun 13
4 min read
Reputation is key to delivering emails successfully and the golden rule to maintaining a solid reputation comes down to one thing – send email to people who want it.
Sender Reputation - man stretching his hand - Photo by Pixabay on Pexels

Today I’d like to help you understand how important your reputation is, explain the different factors involved and what a few of the larger ISPs generally look for.

If you were being called repeatedly by telemarketers at home every time you sat down to dinner despite telling them you were not interested, what would you do? Complain to the phone company? Disconnect your phone? Think about moving to Siberia? Well, that might be a little extreme, but think about it. Complaining to the phone company is a little like hitting the Spam button, disconnecting your phone would be like cancelling your Internet access or changing Email providers, and moving to Siberia would be a little chilly.

Now, what if you had pre-arranged with these people to call you at a certain time about something you were actually interested in? What if they knew a little bit about you, knew your name and could actually pronounce it correctly? What if after telling them you were no longer interested, they never called you again! Would you still move to Siberia?

Get to know your customers! Try and get as much information on them as possible and start sending targeted emails you know will engage their interest.

  • If you say you will email them once a week, do it.
  • If you want to start sending more, ask their permission first.
  • Segment your lists and spend the time creating content you know they will be interested in.

Email Marketing has the highest ROI by far of any marketing strategy, so why would you risk damaging your reputation by not doing all that you can to make sure your email reaches each customer?

Delivering emails successfully is dependant on many things and reputation is a big part of it. Not all ISPs judge reputation the same way, but generally speaking they all look at the following:

  • How many of their users mark your email as Spam (ie: your complaint rate)
  • How many hard bounces you generate (ie: your hard bounce rate)
  • Authentication
  • Content

Your complaint rate should not exceed 0.25% (1 out of 400 emails), if it’s any higher than this you will start having problems. For more information on lowering your complaint rate, please read Complaints! All the Basics You Need to Know to Avoid Them.

Hard bounces are avoided by confirming new leads before adding them to your list. At the absolute minimum you should send them a welcome email which will allow you to remove any invalid addresses in real time and avoid sending to a whole bunch of them at once which will also damage your reputation.

Authentication is important during the initial handshake and will help establish you as a trusted sender. SPF, Domain Keys, DKIM, Sender-ID are all ways of authenticating your emails and although not all ISPs check every one of these, most ISPs will check at least some of them.

Cakemail currently uses all these forms of authentication, but a few of them require modifying your own DNS. For more information on how to set this up, please contact our Delivery team at:

Most ISPs have a section on their Postmaster website about reputation, and they give free access to their guidelines.

Content filters look at a wide variety of things from the domain you are sending From, to words in your content like [Viagra, Spam, Free, Drugs, Credit, Casino, Debt], to the actual html code itself – so try to avoid calling any image files ‘casino.gif’.

If you have a blacklisted domain in your email (even if it’s not the same as the one you are using to send), it might get flagged as Spam.

ISPs use content filters in different ways and some will bypass this process altogether if your From address is in the recipient’s ‘Safe List’ which is why it is so important to add whitelisting instructions in your emails and also during the signup process. Another great way to accomplish this right away is to include it in your Welcome Email.

If you are signing up people legitimately and they want to receive your emails, they should be happy to add you in their contacts.

For more information, please contact our Delivery team.

Remember it’s never too late to start improving your sending practices!

Bye for now,


If you have any questions, Kevin can be reached at: or feel free to use our Help Desk.

Share this

Text Link
This is some text inside of a div block.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.