What is deliverability?
Email deliverability refers to a consumer email being successfully delivered to the email inbox and not within the receiver's spam/junk folders.
Email Delivery
The first component of deliverability is ensuring the email is accepted by the mail server that is responsible for a contact's email address. The inbox placement percentage is a measure of the percent of emails that reach a contact's inbox. An email bounce indicates the email was unable to reach the intended mail server.
Bounces can occur for a variety of reasons including:
Temporary mail server outages: A short term issue with a specific mail provider may result in a bounced email if it was sent during the outage.
Invalid email address: An email address that does not exist in the mail server's system because of a misspelling or is no longer valid for other reasons. These are hard bounces, meaning this is permanent denial by the mail server.
User's inbox settings: Automatic replies, inboxes near their storage limit, or other user settings may result in a bounced email. These are soft bounces, meaning other emails from the same sender may reach the inbox (for example, when automatic replies are not enabled).
Message authentication: If a message is not properly authenticated with DKIM and SPF, it may be rejected by the mail server based on either the sending domain’s DMARC policy, and/or anti-spam policy present at the recipient’s mail system.
Spam Detected: A message is flagged as spam by the recipient’s mailbox provider, third party spam filtering provider, or a blacklisting service referenced by that system.
Email Deliverability
Once an email is accepted by the mail server, the second phase of deliverability is to ensure that the email reaches the inbox instead of thespam/junk folder. The inbox refers to any folder or tab associated with the inbox. Some of the most common factors that impact email deliverability include:
Reputation: Major mailbox providers, such as Google, Yahoo and Microsoft maintain sending reputation for all domains and IPs, which is primarily based on a recipient’s interaction with your emails.
Email Audience: Sending to contacts engaged with your content improves the likelihood of an email reaching the inbox. Messages frequently sent to inactive subscribers or a spam complaint rate that averages more than 0.3% can affect your reputation as a sender, which will have a direct impact on deliverability.
Email Content: While inbox placement to major mailbox providers is primarily determined by reputation, overly aggressive or misleading subject lines can result in lower engagement or increased spam complaints, which can affect reputation directly impacting inbox placement. Engaging email content will also drive a greater amount of revenue to help meet your marketing revenue goals.
Sending Consistency: Long pauses between sending or a sudden increase in send count or the size of an audience can cause messages to be flagged by the mail server as suspicious.
Ensure Deliverability when Moving to Listrak
When moving from one Email Service Provider (ESP) to another, one of the most important aspects of the transition is the warmup. The warmup process involves sending to the most engaged email subscribers in the new ESP to ensure that you begin with a high level of engagement on the new IP.
⚠️ Immediately sending to all of your contacts, or even a large group of contacts, can severely damage the reputation of the new IP and result in your emails being filtered to the SPAM/junk folder. The click tracking and bounce domain are unique to the ESP, resulting in the new click tracking and bounce domains from Listrak being unrecognized by the mailbox providers.
The warmup allows the mail servers to "get to know" your new sending volume. You can use your previous sending domain or subdomain to provide a smoother transition to Listrak. Sending to the most engaged contacts during this process ensures that the mailbox providers record engagement from this new sending volume. Anti-spam systems used by these mailbox providers use positive message engagement as a sign of trustworthiness.
The warmup process at Listrak
A warmup is a fully customized process led by the Listrak Deliverability team.
Before you can begin the IP Warmup process, you will need to complete the following:
Brand your Listrak Account.
Ensure your domain has a DMARC policy in place.
Export details about your contacts and their message engagement from your previous ESP.
Export activity such as:
Last Open Date
Last Click Date
Work with your Account Manager to identify any additional data needed
Based on the list you provide, the Deliverability team will create a customized plan by identifying your most engaged contacts. On the first day of your warmup, you will send to a very small number of highly engaged contacts and gradually build volume as you transition other segments of your database to Listrak. A typical warmup averages about 2-3 weeks, depending on send frequency.
Mailbox providers have set strict limits on how much volume they are willing to accept from new IPs, so if you’ve been assigned a dedicated IP, the Deliverability team recommends starting small and doubling send volume with each campaign until your new IP has been completely warmed. You will also receive a list of contacts within each audience set up in Listrak, so that you can easily exclude them from sends your previous ESP.
An example of a warmup schedule is listed below. This is not specific to your account.
Warmup Segment # | Total Contact Size |
1 | 250 |
2 | 500 |
3 | 1,000 |
4 | 2,000 |
5 | 4,000 |
💡 The specific number of contacts per send and the length of your warmup process will depend on the size of your list, the number of active contacts on the list, and any deliverability issues you have previously experienced. The Deliverability team will review all available data and create an optimal warmup plan to ensure a successful transition.
Best Practices for Positive Deliverability
Once you have completed your warmup, you will want to ensure that your deliverability is healthy.
💡 These are general guidelines for positive email performance. If you have any concerns, work with your Account Manager and, if needed, set up a meeting with a member of the Deliverability team for recommendations for your specific situation.
Keep your list healthy. You should never buy or rent an list of contacts in an effort to grow your subscriber base. Clear messaging about what a contact is opting into drives high quality acquisition. Once you have acquired these contacts, be sure to regular audit them to identify lapsed contacts.
Consistently send to your engaged audience.
Develop a send cadence to send to your less engaged contacts with a lower frequency. Regular audits allow you to change a contact's message frequency if their engagement level changes.
Honor a contact's email preferences for the types or frequency of messages (if collected).
Avoid using spammy words in subject lines (just check your own SPAM folder and you'll see patterns in the subject lines).
Create engaging message content to drive opens, clicks, and other types of engagement.
Make it easy to unsubscribe so a contact will unsubscribe instead of marking the message as SPAM. Easily identify your unsubscribe link in your emails (and include HELP and STOP compliance language in your SMS messages) to make it easy to unsubscribe.
Stay up to date on changing compliance laws and changes in mail server policies.
Other Activities to Consider
In addition to ensuring you are sending engaging content to those who would like to receive messages, you can take additional steps to identify contacts who you may want to exclude from your sends.
Create a re-engagement flow to provide a 'last chance' for contacts to engage with the brand before marking them as un-engaged so they can be filtered out of sends or unsubscribing them from your marketing program.
Monitor your bounces.
Do a quarterly review (or more frequent) to identify contacts who have frequent soft bounces.
Overlay an activity filter to determine if these contacts have opened or clicked the messages, even if they frequently bounce.
Mark contacts who have not engaged as chronic bounces so they can be filtered out of sends or unsubscribed from your marketing program.
📑 Additional Resources
Branding Your Listrak Account
Setting Up a DMARC Policy