How to set up custom rules for email verification in Emailable

If you’ve got a list of emails to clean, but “one size fits all” verification isn’t cutting it, you’re probably looking for a way to set your own rules. Maybe you want to enforce stricter checks for certain domains, or flag anything that smells like a burner address. If that sounds like you, this guide is for you.

We’re digging into how to set up custom rules in Emailable, a tool that goes beyond the basics by letting you decide what counts as a “good” email. I’ll walk you through the process, point out what’s actually useful, and call out what to skip — so you don’t waste time fiddling with settings that don’t move the needle.

Why bother with custom rules?

Most email verification tools run the same checks for everyone: syntax, domain, mailbox existence, disposable detection, and so on. That’s fine for a lot of people, but sometimes you need more control:

  • Maybe you never want to accept any role-based addresses (think info@ or sales@).
  • Or, you’re tired of seeing “safe to send” ratings on Gmail addresses that are obviously bots.
  • Or, you want to automatically flag emails from certain countries or industries.

Default settings can’t keep up with every edge case. Custom rules give you a way to fit verification to your business — not the other way around.

What are custom rules in Emailable?

In Emailable, custom rules are basically filters you create to override or add to their standard verification logic. Each rule is a condition (like “if the email is from a free provider”) and an action (“mark as invalid,” “set as risky,” or “add a tag”).

You can use these to:

  • Block, flag, or tag emails based on domain, pattern, or other properties.
  • Override Emailable’s default results (e.g., mark “catch-all” mailboxes as invalid).
  • Route emails for manual review if they match tricky conditions.

You don’t need to know how to code. Rules are set up in the dashboard using dropdowns and fields. But you do need to know what you want to accomplish — otherwise, you’ll just create noise.

Step 1: Decide what you actually need to customize

Before you even log in, stop and make a quick list:

  • What kinds of emails keep slipping through that shouldn’t?
  • Are there domains, patterns, or behaviors you want to treat differently?
  • Do you really need to block certain types, or just tag them for review?

If you’re not sure, start simple. Too many rules can make your results messy and hard to trust. Focus on your biggest pain points.

Pro tip: Don’t set rules just because you can. Every custom rule is a potential maintenance headache later.

Step 2: Log into Emailable and find the custom rules section

  • Sign in to your Emailable dashboard.
  • In the left-hand navigation, look for “Verification Rules” or “Custom Rules.” (Emailable sometimes moves this around, but it’s usually not buried.)
  • If you don’t see it, double-check that you have admin access. Some accounts restrict this feature.

You’ll land on a page listing any rules you’ve already set up, plus an option to add new ones.

Step 3: Create a new rule

  1. Click the button to “Add Rule” or “New Rule.”
  2. Give your rule a clear name — not just “Rule 1.” Try something like “Block Yahoo Aliases” or “Flag Role-Based Emails.”
  3. Choose the condition (the “if” part):
    • You’ll see a dropdown of options, like:
      • Email domain (e.g., ends with “@gmail.com”)
      • Email pattern (e.g., contains “test”)
      • Type (e.g., disposable, role-based, catch-all)
      • Verification status (e.g., risky, invalid)
      • Custom tags or metadata (if you use those)
  4. Set the action (the “then” part):
    • Actions usually include:
      • Mark as invalid
      • Mark as risky
      • Tag (add a label for later review)
      • Exclude from results

You can stack multiple conditions if you want (like “domain is gmail.com” and “contains ‘test’”). But again, don’t overcomplicate unless you really need to.

Step 4: Test your rule before you go live

This part is easy to skip, but don’t. A badly written rule can nuke valid emails or let junk slip through.

  • Most dashboards let you preview how your rule would have affected previous verification jobs.
  • Try it on a sample list. Look for false positives (good emails flagged) and false negatives (bad emails missed).
  • If you’re not sure, make the rule “tag only” at first, so you can review what it catches.

Pro tip: Avoid using “Mark as invalid” until you’re sure the rule is working. It’s safer to tag or flag first.

Step 5: Put your rule into production (and monitor it)

Once your rule is tested:

  • Save and enable it.
  • Run a new verification job and check the results.
  • Watch for weird patterns, like a sudden spike in invalids or tons of emails tagged for review.

If something’s off, edit or disable the rule. Don’t be afraid to tweak — rarely does anyone get this perfect on the first try.

Useful custom rules (with honest pros and cons)

Here are some common rules people set up, and whether they’re really worth it:

1. Block all disposable addresses

Condition: Email is disposable
Action: Mark as invalid

Worth it?
Yes, almost always. Disposable emails are usually garbage. But beware: some real users (e.g., privacy-minded folks) may use these, so check your audience.

2. Flag all role-based addresses (like sales@, info@)

Condition: Email is role-based
Action: Tag or mark as risky

Worth it?
Depends. These aren’t always spam — some small businesses do use these as real inboxes. If you’re B2B, you may want to just tag, not block.

3. Block/flag free email providers (Gmail, Yahoo, Outlook)

Condition: Domain is in list of free providers
Action: Tag or mark as risky

Worth it?
Maybe. Blocking free providers is rarely a good idea — you’ll lose legit emails. But tagging them can help you segment or trigger extra checks.

4. Block obvious spam patterns

Condition: Email contains “test,” “spam,” or random strings
Action: Mark as invalid or tag

Worth it?
Sometimes. This can catch junk, but can also snag real accounts (e.g., “test@company.com” might be a real test user). Use with caution.

5. Override “catch-all” mailbox status

Condition: Email is catch-all
Action: Mark as risky or tag

Worth it?
Yes, if you’re tired of “catch-all” domains showing as safe when they’re actually black holes. But don’t just block them — some real businesses use catch-all on purpose.

What to skip (unless you really know what you’re doing)

  • Complex regex rules: Tempting, but easy to mess up. Unless you’re comfortable with regular expressions, keep it simple.
  • Blocking by country/region: Risky. You’ll probably block real users and create headaches.
  • Too many overlapping rules: More rules = more confusion. If something’s not adding value, delete it.

Tips for keeping your custom rules sane

  • Start with one or two rules. You can always add more later.
  • Review rules quarterly. What made sense six months ago might be irrelevant now.
  • Document why you made each rule. Future-you (or your teammates) will thank you.
  • If in doubt, tag — don’t block. You can always tighten things up once you’re sure.

Bottom line

Custom rules in Emailable are powerful, but easy to overdo. Focus on the problems that actually bug you — not every possible edge case. Start simple, test carefully, and don’t be afraid to backtrack if a rule isn’t working out.

Email verification isn’t magic. It’s just another tool to help you cut down on junk and keep your list clean. Make your rules work for you, not the other way around.