Custom QA lets you turn your team's brand and quality standards into automated checks. Define a rule once (for example, "the subject line must be between 40 and 60 characters" or "every instance of MonsterCard must be spelled correctly") and the system runs that check against every email render, flagging anything that fails before send.
This walkthrough covers the three things you'll do most often: setting up your rule library, running QA against an email, and reading the results.
ℹ WHAT YOU'LL LEARN IN THIS GUIDE 1. How to find the Custom QA settings page 2. How to add pre-built rules from the Rule Catalog 3. How to write your own custom rules 4. How to read the QA results and act on failures |
Setting up your rule library
Before Custom QA can check anything, it needs a list of rules to check against. You build that list on the Custom QA settings page.
Step 1. Navigate to Custom QA
1. Click the Settings gear icon in the top navigation bar (between the brand switcher and the help icon).
2. From the dropdown, choose Creative Rendering (last item in the list).
3. On the Creative Rendering Settings page, select Custom QA from the left-hand menu.
The Settings dropdown. Custom QA lives under "Creative Rendering" at the bottom of the list.
Once selected, you'll land on the Custom QA settings page shown below.
The Custom QA settings page is where you manage every rule that runs against your emails.
Step 2. Understand the page layout
Three areas to know on this screen:
• Description and example. The grey panel near the top shows an example of what a well-written rule looks like — useful when you're writing your first one.
• Rule List. Every active rule for this brand, with its category, definition, an enable/disable toggle, and edit/delete actions.
• Rule Catalog and Create Rule buttons. Top-right of the Rule List. The catalog is the fastest way to add common rules; Create Rule is for anything brand-specific.
Adding rules from the Rule Catalog
The Rule Catalog is a library of pre-written rules grouped by category. If you're setting up Custom QA for the first time, start here — most teams will find that 70-80% of what they need is already in the catalog.
Step 1. Open the catalog
Click Rule Catalog in the top-right of the Rule List.
The catalog opens as a modal over the settings page.
The Rule Catalog is grouped into categories; each category shows how many of its rules you've added (e.g. 4/4).
Step 2. Browse and add rules
Click any category header (Subject Line & Preview, Content & Copy, Design & Brand) to expand it.
Read each rule's description to decide whether it applies to your brand.
Click the Add button next to a rule to add it to your set. The button changes to a green ✓ Added state once it's in your library.
Use the search field at the top to find a specific rule by keyword (e.g. "preheader", "alt text").
When you're done, click Close. Your additions are saved automatically.
✦ TIP — START SMALL Don't enable every rule on day one. Pick 5–10 rules that map to your team's most common QA mistakes, run a few emails through, and add more once you're comfortable with the workflow. Every active rule adds to your QA report, and a long report is harder to scan. |
Writing your own custom rules
When the catalog doesn't cover something — a brand-specific spelling, a product name, a legal disclaimer your team always includes — write your own rule.
Step 1. Open the Create Rule dialog
From the Custom QA settings page, click Create Rule in the top-right of the Rule List.
The Create Rule form. The pink panel at the bottom shows tips for writing rules the system will interpret reliably.
Step 2. Fill out the form
Rule Name. A short label that will appear in the Rule List and in QA results. Keep it 2–5 words. Example: "MonsterCard Spelling".
Category. Pick the category this rule belongs to (Subject Line & Preview, Content & Copy, Design & Brand, Links & Tracking). Categories group your results so they're easier to scan.
Rule Definition. The actual instruction the system will follow. This is the most important field (see the tips below).
Include links validation. Turn this on if your rule needs to check URL behavior (e.g. tracking parameters, redirect targets, masked links).
Click Create. The rule is added to your Rule List and is enabled by default.
✦ WRITING EFFECTIVE RULE DEFINITIONS • One rule per check — keep it clear and focused. Don't combine "check the subject line length AND check capitalization" into one rule. • Say where to look if necessary — subject line, body, footer, header, alt text, etc. • Reference a standard when one exists — e.g. WCAG, CAN-SPAM. • Tell the rule what to report — e.g. "Report the actual character count" or "Report the line number where the issue occurs." |
Examples of well-written rules
Rule Name | Rule Definition |
Subject Line Length | Verify the subject line is between 40 and 60 characters. Report the actual count. |
MonsterCard Spelling | Verify that the copy says "MonsterCard" and never "MonstieCard". Report the line number for any mismatch. |
Hidden Preview Text | Check for a hidden preheader element with non-empty text content. Fail if absent or empty. |
Trademark Superscript | Ensure all trademark (™), registered (®), and service mark (℠) symbols are wrapped in <sup></sup> tags. Fail if any such symbol appears outside of sup tags. |
Managing your existing rules
Each row in the Rule List has controls for managing that rule:
• Enabled toggle. Turn a rule on or off without deleting it. Useful when you want to pause a rule for one campaign without losing the definition.
• Edit (pencil icon). Open the rule in the Create Rule form to change its name, category, or definition.
• Delete (trash icon). Permanently remove the rule. Use the toggle instead if you might want it back later.
Running QA and reading the results
Once your rules are set up, every email render is automatically scored against them. The Custom QA results panel shows you what passed, what failed, and exactly where to look in the HTML to fix anything broken.
The Custom QA results page. Failures show exactly which line of HTML triggered them, with the editor open on the right.
Anatomy of the results page
Element | What it tells you |
Sendability score | A single percentage that summarizes how ready this email is to send. The example above shows 45%, meaning roughly half of the rules passed. |
All / Pass / Fail / N/A counts | Quick filter chips. Click any one to narrow the list below. "N/A" means the rule didn't apply. For example, a trademark-symbol rule on an email with no trademarks. |
Category sections | Results are grouped by the same categories you saw in the catalog (Content & Copy, Links & Tracking, etc.). Each section can be collapsed. |
Rule cards | One card per rule. Shows the rule name, its definition, the result, and, for failures, the exact line of HTML and a description of the issue. |
All Categories filter | Top-right of the results panel. Use this to focus on one category at a time when you have many rules enabled. |
Re-run button | After fixing an issue in the editor, click Re-run to re-score the email without leaving the page. |
Version dropdown | Compare the current QA results against past versions of the same email. |
Editor / Visual Preview | The right-hand panel. Switch between raw HTML (with line numbers, failures link directly to the offending line) and a rendered preview. |
Understanding the three result states
✓ PASS The rule was checked and the email met the requirement. | ✗ FAIL The rule was checked and the email did not meet it. The card explains what went wrong and where. | — N/A The rule didn't apply (e.g. a trademark check on an email with no trademark symbols). |
How to Act on a Failure
Take the "MonsterCard vs. MonstieCard" failure from the screenshot above. Here's what the card tells you and how to fix it:
Read the rule definition. "Verify that the copy says MonsterCard vs. MonstieCard." Clear and unambiguous.
Read the failure detail. "Line 312 — The email uses 'MonstieCard' in the alt text on line 312 ('Your MonstieCard mobile platform visual') instead of 'MonsterCard'." The system tells you the exact location and the exact wrong word.
Jump to the source. Click the line reference (or scroll the editor on the right to line 312) to see the offending HTML in context.
Fix and re-run. Correct the typo in the editor, then click Re-run at the top of the page. The rule should now show Pass.
ℹ FIXING ACROSS VERSIONS Re-running QA creates a new version. Use the Latest dropdown in the top-right to compare results across versions and confirm a fix didn't break anything else. |
Frequently asked questions
Are my custom rules shared across brands?
No. Rules are scoped to the brand selected in the top-right brand switcher. Each brand has its own Custom QA library.
Can I temporarily disable a rule without losing it?
Yes. Use the Enabled toggle on the Rule List. The rule stays in your library and can be re-enabled at any time.
How specific can my rules be?
Very. The system reads natural-language rule definitions, so you can reference specific words, phrases, line numbers, HTML elements, character counts, regex-like patterns, and standards (WCAG, CAN-SPAM). The more precise the rule, the more reliable the result.
What if I get a false positive or false negative?
Edit the rule definition to be more specific. The most common cause of a flaky rule is ambiguous wording. For example, "check the subject is good" is too vague, but "verify the subject line is between 40 and 60 characters and starts with a capital letter" is unambiguous.
Do I have to re-run QA after every change?
Yes — click Re-run after each edit. This keeps results in sync with the current version of the HTML, and creates a new version you can compare against earlier ones.
Custom QA is in BETA - what does that mean?
The feature is fully usable in production but the underlying scoring model is still being tuned based on real-world feedback. Use the help icon in the top nav to send issues to our team.