How to improve email deliverability

Email deliverability is a measure of how your emails can successfully reach your users' inbox without bouncing or being marked as spam. If you have issues with high bounces, flagging spam filters, or low engagement, you may have email deliverability issues. 

When it comes to infrastructure Prefinery has got you covered from keeping our IPs clean, throttling to the ISPs, properly monitoring and handling bounces and spam complaints, and keeping up with industry-standards and things like DKIM

We also provide you the option to set up your own custom SMTP server for your campaign if you want more control on the infrastructure aspect.

With that said, each project can be unique and may have its own requirements for its emails that may affect deliverability. Also, your sending reputation lies in how you handle communication with your users. 

If you are having issues with users receiving your emails, or would just like to optimize the delivery of your campaign's emails, here are some tips: 

Enable double opt-in

Infrastructure plays a huge role, but if you are sending email to people who don’t want or expect it, you’re going to have delivery issues. Having good sending practices is the priority to having your email get to the Inbox. 

By enabling double opt-in on your project where the user has to click a confirmation link on an email after signing up, once they opt in it can be a way for them to unknowingly tell their spam filter "I'm okay with receiving emails from this sender, or emails like this in general". They’re also less likely to report messages from your domain as spam. If messages from your domain are often reported as spam, future messages are more likely to be delivered to the spam folder (not just for that one user, but for others too). 

Not only does a confirmed opt-in protect you from erroneous signups and spambots, confirmed opt-in lists also see better results with almost every engagement metric. 

If you'd rather have double opt-in turned off, make sure that your users had recently expressed consent to joining your campaign so they expect your email and will not mistakenly mark it as spam or unsubscribe immediately as defined here: Prefinery Acceptable Use Policy

To learn more about the benefits of double opt-in, check out our guide here: What Is Double Opt-In and Why You Need It

Have a verified return-path

To be able to send Prefinery emails with your domain email address (e.g. as the sender, you'd need to get the sender address confirmed and its domain verified. 

Verifying the domain helps ensure that your sent email arrives in your user's inbox. Additionally, emails signed by your own domain will look as if they've been sent directly from you, rather than delivered by 

Domain verification requires the DKIM to be verified. A verified return-path, while optional, may also help with improving the chances of your emails getting through some recipients as it is used by receiving email domains to check for SPF alignment

To learn more about how you can fully verify your sender address domain, including a return-path, please see: How do I verify my domain?

Ensure your domain isn't on a blacklist

A domain blacklist is a list that's constantly being maintained in real-time, and is used to keep track and identify domains that are known to send spam. They’re used by internet service providers (ISPs), free mailbox providers (e.g. Gmail, Yahoo, etc.), anti-spam vendors and other services that deals with inbound emails to automatically filter out and prevent spam from getting into their systems. 

Since Prefinery requires you to use your own sender address domain for your campaign emails, your domain is subject to these blacklists. High spam complaints (user marking your email as spam) and importing bad email lists (list may not be opted in or current) are all it takes for your domain to get blacklisted. It also could've been blacklisted already prior to you using Prefinery. 

It's good practice to check every now and then why your project is getting spam complaints, if your spam rate is increasing, or when it gets flagged for a review due to a high spam rate by going to Analytics > Email > Logs > Spam Complaints or checking the individual user's profile like as shown below: 

The returned details can indicate whether or not your domain is currently blacklisted.

If it is, or even if it isn't, we recommend that you use a blacklist check tool like this one by MXToolBox which checks your domain against popular blacklists. 

If you find that your domain is on a blacklist, don't panic. You must first ask yourself (or discuss with your team): "Why is the domain blacklisted?" to determine why this happened and then work on resolving it. Here are some examples on what to look into: 

  • Is there a history (even before using Prefinery) of the domain being used improperly as a sender address domain e.g. to send spam/unsolicited emails?
  • Did you import a bad email list e.g. imported users had to idea why their email address ended up on the list (especially true for purchased email lists)?
  • What is causing the user to mark your email as spam?
  • Do you have a verified return-path? How about double opt-in for your project?
  • Are you adhering to industry email best practices and proper email etiquette?

Once you've figured out and taken action on the email deliverability issue, you need to go to the blacklisting site and ask for your domain to be removed. Some offer a self-service removal tool and others require you to go through a removal process. Please note that if you haven’t already fixed your email deliverability problems, you’re likely get blacklisted again soon after. 

If your project/email was flagged for manual review due to this issue (besides the notification on your project dashboard, you'll receive an automated email about it too), please let us know. Until then, Prefinery has to pause email sending to avoid furthering the spam rate. 

If we don't hear back from you, or if your spam rate becomes incredibly concerning, you'll get another automated email from our system saying we cannot send email for you moving forward and you need to set up your own ESP which of course isn't necessary - just as soon your domain is delisted from the blacklist(s), let us know, and we'll immediately reinstate email delivery, and all the emails queued (during the review when sending was paused) will be sent to your users. 

Customize your emails

For every newly created project on all Prefinery accounts, email messages are automatically created using a template message from the subject line to the email body. The same goes for the email layout used. This means all Prefinery campaigns start out with nearly identical email messages. 

For this, we highly recommend that you update and personalize your email messages to match your unique brand and voice. You can refer to the following guides on how to do so: 

Learn from your users

From your project dashboard, if you go to Email > Suppressions you'll find the users that either got hard bounced, unsubscribed, or submitted a spam complaint for the email you sent to them. Checking on each of these users' profiles you'll find which email was last sent to them which made them unsubscribe or file a spam complaint. 

Knowing these will give you an idea on how to better improve your emails and make sure you don't come across as spammy or unexpected to them. 

If your emails are automatically ending up in your users' spam folder even with the user not doing anything, there are a couple of things you should look into especially with your email content, and even activities outside of your Prefinery campaign that still impacts it. 

You can check out our separate guide here: How to prevent my email from going to the spam/junk folder

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