What is email deliverability?

Email deliverability is the ability to deliver emails to your recipient's inbox (including tabbed inboxes, such as Google’s Promotions tab). 


Why does email deliverability matter?

Low email deliverability means your messages are not reaching your subscribers’ inboxes and makes your email campaigns ineffective. That’s why it's important to consider factors that affect your email deliverability.


Factors that affect deliverability

  1. Your sender reputation

    1. Sending domain reputation

    2. Recipient engagement

    3. Bounce, spam reports and unsubscribes

  2. Infrastructure reputation

  1. The content of your email

Each mailbox provider (Gmail, Outlook, Yahoo etc) will have different weightage for each of the above factors and is not publicly available.

Sender reputation

  • Recipients opening, replying to, and forwarding emails impact your reputation positively, while recipients ignoring the emails, deleting them, reporting them as spam, and unsubscribing impact your reputation negatively
  • If the ISP(Internet Service Provider) sees a sudden spike in emails sent from your domain, it might move your emails to spam. Staggering your emails and sending them in batches helps improve your reputation
  • Recipients marking your emails as spam or otherwise complaining to the ISP about the messages
Note: A spam trap is an email address specifically created by ISPs or anti-spam organizations to catch spammers. If your email lands into a spam trap, your IP address and domain can be blacklisted, resulting in a loss of deliverability for all future emails. 
  • Your domain inclusion on different blacklists
  • Bounced emails because they were sent to unknown users or invalid email addresses
  • Spike in recipients unsubscribing to your emails


Infrastructure reputation 
A history of low spam complaints and bounce rates makes your sending IP more trustworthy, while a high number of complaints will put a dent in your IP’s credibility.


Freshmarketer Shared IP reputation

  • Freshmarketer shared IP address is shared between you and other senders. A shared IP address combines the  IP reputation of everyone to facilitate set-up and deliverability for all.
  • You will usually be grouped with senders who have similar sending volumes. The reputation is built on the activity of all senders who are using the same sending IP.

Dedicated IP reputation

  • A dedicated IP address is used to send only your email. In this case, your emails are sent from an IP that is exclusive to you. The reputation is solely based on your actions.
  • Dedicated IP is recommended when you have higher volumes of emails to send. Also, it is a preferred option to improve email campaign performance

Email Content

Lack of certain hygiene factors in your email content might affect your deliverability such as:

  • Image-only emails. Be sure to include some text in your emails, including alt-text

  • Numerous links to external domains. Most of the links in your emails should lead back to your website.

  • All caps text or using excessive symbols. 

  • Third-party URL shorteners like bit.ly

  • Using flashy words like ‘Free’ or ‘once in a lifetime’ or ‘Urgent’ in the subject lines and content of the email 

Email deliverability best practices

You can make sure your emails land in the primary inboxes of your receivers by following some best practices.

Maintain list hygiene

If you are importing your email lists to the account, make sure that you clean them first. Remove any invalid or inactive emails by looking at data like open rates, bounce rates, etc. from your previous email service provider. 

Make it a practice to clean your lists regularly to keep them relevant and updated.

Build lists with opted-in recipients

Keep separate lists for types of opt-ins. For example, the people who signed up for your newsletter vs. the people who subscribed for product updates could be expecting different information. If you send messages with information that your recipients might not be interested in, it will lead to higher unsubscribe rates and low engagement.

Enable double opt-in by having new subscribers confirm their email when they first opt in. This will prevent invalid emails or typos in your email list.

Send engaging content

One of the major factors that determine your deliverability is your email content. If your recipients are not interested in the email content, they will ignore your emails or worse, report you as spam. Always send high-quality, engaging content that your subscribers opted-in to see. Personalize emails to make it relevant to your audience. 

Make it easy to unsubscribe and manage preferences

An unengaged user not only decreases engagement rates but could also report your emails as spam which will significantly hurt your sender reputation. Include a link in all your emails to unsubscribe and manage email preferences so that your recipients can choose the type of emails they want to receive or unsubscribe if they want to.

Segment engaged audience

Create a segment for your engaged audience and send campaigns to them. Since the likelihood of them engaging with your emails would be higher, it will help you increase your reputation for future campaigns.

Stick to a schedule

To keep healthy open and engagement rates, stick to a schedule that works for your recipients. Sending too many emails to your unengaged audience will hurt your reputation, and sending too few emails to engaged profiles can lead to lost opportunities. Maintain a healthy balance by creating thorough segments and sending schedules. 

As you understand email deliverability, you can also check out the next steps to warm up your sending infrastructure.