Sending Pardot Emails to Large Lists – Guidance and Tips

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Sending a mass email through Pardot can be damaging to your overall email deliverability if checks aren’t carried out in the preparation stage.

There’s no better time to address this topic. The Coronavirus outbreak has seen many organisation stepping up to the mark to announcing their operational procedures and heartfelt wishes to customers, subscribers, and employees alike. My inbox has been flooded with messages like these for days.

Such important messages need to have the maximum reach, so naturally, often involve large sending lists.

The only (vaguely similar) event that springs to mind is GDPR and the ‘Permission Pass’ campaigns organisations sent out in the run-up to the legislation. What’s different this time around, is the preparation time; COVID-19 has spread exponentially, fast, exponentially, with nowhere near the same warning and predictability we had for GDPR. The default response is ‘panic mode’ while everyone makes sense of what is going on.

Risks When Sending Large Emails

Whether large emails are sent during emergency periods, or ‘BAU’ generally, there are risks to your overall email deliverability you must mitigate:

  • Invalid email data (more later)
  • Spam Filters: these filters are designed to block ‘unsolicited bulk email’ from recipient inboxes. Filters can even pick up on unusual behaviour, for instance, your organisation doesn’t send large emails often, it would look suspicious to the ESP.
  • Spam Complaints (more later)


I put together another checklist in the past, titled “10 Pardot Email Prep Checks Before Sending” which were relevant to any email send – large or small – so check these points out too:


This checklist contains additional best practice you should follow, aimed especially for sending large emails.

Segment Your List

There may be obvious categories you can use to segment your database, for example, ‘Customers’, ’Subscribers’ etc.

The fastest way to compile this data is by using a Dynamic List, which will automatically segment your Prospect database according to criteria you set – and will continue to do so if a Prospect’s data changes.

My recommendation is that you also pull the same report in Salesforce, to cross-reference what you expect from your Salesforce Leads and Contacts data, with what Pardot can see.

Watch Out for Risky Prospects

GDPR brought ‘dirty’ data acquisition and list building practices to light. There’s been a growing awareness on how to properly capture, process and store data – but some data will slip through the cracks, namely old data, or data added to Salesforce by the sales team.

Be aware of Prospect data that:

  • Haven’t confirmed opt-in (double opt-in)
  • Haven’t been active in Pardot for a certain length of time
  • Were part of purchased lists
  • Are from an unknown source

Validate the Email Data

There’s a high chance that your list contains data that hasn’t been touched in a while. Email address data quality deteriorates quickly – especially with B2B audiences, where Prospects leave the business or email domains are updated.

Use an email validation tool to estimate how much of your database is predicted to cause an email bounce. There are 4 varied options in this post to trial.

! Remember that Pardot’s bounce rate tolerance is 10% – in other words, you must achieve 90%+ deliverability rate.

Split the List

Once you have Dynamic Lists set up, they still may be too big, especially if this is out-of-character behaviour for your organisation.

Use the handy ’Split list’ functionality to send your message out gradually:

Run a Spam Analysis

Pardot has a built-in Spam Analysis tool, which is part of the ‘Advanced Email Analytics’ feature found under the Email Builder ‘Testing’ tab.

For a second opinion, I like to use It’s free, simple to use and the results are descriptive.

Email Types: Marketing vs. Operational

There are two types of emails:

  • Marketing AKA Promotional
  • Operational ‘non-marketing’ AKA Transactional

The message you are planning to send may not be promotional, but in fact, may fall into the ‘Operational’ category if one of the following categories applies:

  • Necessary to health and safety regulation
  • Communicates terms of service changes
  • System status notices
  • Internal emails within your organisation:

There are other categories listed here, but I picked out the likely one for COVID-19 notifications.

Operational email sends by-pass the ‘email opt-out’ field, so BE CAREFUL and consider the content of your email carefully!


These are challenging times, but Marketers are stepping up to the mark to communicate essential messages to their customers, subscribers, and fellow co-workers. Effective communication is so meaningful at this time. Our thoughts go out to everyone affected by the evolving COVID-19 situation – stay healthy, and stay positive (even with a hearty dose of Salesforce).

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