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Watch an alert arrive. Nine planted mistakes, all named.

We sent a test campaign from our own Klaviyo account on 9 October 2026, with mistakes we planted. This is the alert our checks sent back.

Get early access hello@synapseretention.com

The 16 seconds, step by step

Which copy of the email to show

Black Friday early access: 20% off everything

Synapse Demo

demo@synapseretention.com

To our address without a first name ·

Our test campaign, as our address without a first name received it. At the top, a “View this email in your browser” link. It greets “Hi ,” and offers the codes TAKE15 and DOUBLE10. Then a “Shop early access” button, a line opening “*|FNAME|*,” and a “See everything in early access” link. Its last line reads “This is the Flow Watch demo's test campaign. Every mistake in it is planted.”

Problem 2 in the alert: Subject and code disagree

The subject line says 20% off, but the code TAKE15 gives 15% off.

What to do: Make the subject line and the code give the same discount. Otherwise a subscriber who opens for 20% is given a code for 15%.

Only in the copy to our address without a first name.

Problem 1 in the alert: Proof it's from you

This email from synapseretention.com failed the check that proves it really came from you. Gmail says mail that breaks its rules may not arrive, or may land in spam.

What to do: Turn on a branded sending domain: it proves emails come from your web address.

Problem 6 in the alert: Links that go nowhere

The link “View this email in your browser” goes nowhere: it points to “*|ARCHIVE|*”. It's how Mailchimp writes a fill-in field, which your platform doesn't fill in.

What to do: Point it at your email platform's own “view in browser” link, or take it out.

Problem 9 in the alert: A greeting with no name

The greeting reads “Hi ,” for subscribers who didn't give a first name.

What to do: Give the name a fallback, like “there”, so it reads “Hi there,”.

Only in the copy to our address without a first name.

Problem 2 in the alert: Subject and code disagree

The subject line says 20% off, but the code TAKE15 gives 15% off.

What to do: Make the subject line and the code give the same discount. Otherwise a subscriber who opens for 20% is given a code for 15%.

Only in the copy to our address without a first name.

Problem 4 in the alert: One code, two discounts

The code DOUBLE10 is given two different discounts in one email: 10% off and 25% off.

What to do: Give the code one discount everywhere, and check which one it takes at checkout.

Problem 5 in the alert: Discount links without a code

The link “Shop early access” applies the code “CODE”, not a real code.

What to do: Put the real code in the link, where it says CODE.

Problem 8 in the alert: Text subscribers shouldn't see

Subscribers see “*|FNAME|*” where their first name should be. It's how Mailchimp writes a fill-in field, which your platform doesn't fill in.

What to do: Use your email platform's own first-name field, with “there” for people without a name.

Problem 7 in the alert: Links that may not open

Some email apps may not open the link “See everything in early access”: no https:// at its start.

What to do: Change it to https://www.synapseretention.com/early-access so every email app opens it.

Problem 4 in the alert: One code, two discounts

The code DOUBLE10 is given two different discounts in one email: 10% off and 25% off.

What to do: Give the code one discount everywhere, and check which one it takes at checkout.

Black Friday early access: 20% off everything

Synapse Demo

demo@synapseretention.com

To our address with a first name ·

Our test campaign, as our address with a first name received it. At the top, a “View this email in your browser” link. It greets “Hi Rowan,”, says “Take 15% off your first order.” and offers the code DOUBLE10. Then a “Shop early access” button, a line opening “*|FNAME|*,” and a “See everything in early access” link. Its last line reads “This is the Flow Watch demo's test campaign. Every mistake in it is planted.”

Problem 3 in the alert: Subject and email disagree

The subject line says 20% off, but the email says 15% off.

What to do: Make the subject line and the email give the same discount.

Only in the copy to our address with a first name.

Problem 1 in the alert: Proof it's from you

This email from synapseretention.com failed the check that proves it really came from you. Gmail says mail that breaks its rules may not arrive, or may land in spam.

What to do: Turn on a branded sending domain: it proves emails come from your web address.

Problem 6 in the alert: Links that go nowhere

The link “View this email in your browser” goes nowhere: it points to “*|ARCHIVE|*”. It's how Mailchimp writes a fill-in field, which your platform doesn't fill in.

What to do: Point it at your email platform's own “view in browser” link, or take it out.

Problem 3 in the alert: Subject and email disagree

The subject line says 20% off, but the email says 15% off.

What to do: Make the subject line and the email give the same discount.

Only in the copy to our address with a first name.

Problem 4 in the alert: One code, two discounts

The code DOUBLE10 is given two different discounts in one email: 10% off and 25% off.

What to do: Give the code one discount everywhere, and check which one it takes at checkout.

Problem 5 in the alert: Discount links without a code

The link “Shop early access” applies the code “CODE”, not a real code.

What to do: Put the real code in the link, where it says CODE.

Problem 8 in the alert: Text subscribers shouldn't see

Subscribers see “*|FNAME|*” where their first name should be. It's how Mailchimp writes a fill-in field, which your platform doesn't fill in.

What to do: Use your email platform's own first-name field, with “there” for people without a name.

Problem 7 in the alert: Links that may not open

Some email apps may not open the link “See everything in early access”: no https:// at its start.

What to do: Change it to https://www.synapseretention.com/early-access so every email app opens it.

Problem 4 in the alert: One code, two discounts

The code DOUBLE10 is given two different discounts in one email: 10% off and 25% off.

What to do: Give the code one discount everywhere, and check which one it takes at checkout.

Synapse Retention

Campaign sent · Alert sent

Synapse Demo: 9 problems in “Black Friday early access: 20% off everything”

Our own test campaign, sent from our Klaviyo account on 9 October 2026. Its mistakes were planted. This is the copy our address without a first name received.This is the copy our address with a first name received. Choose a number to read what the alert said.

Our own test campaign, with mistakes we planted

Campaign sent
Alert sent
In the alert
9 problems
Our test
, Vienna time
From
watch@synapseretention.com
Subject
Synapse Demo: 9 problems in “Black Friday early access: 20% off everything”

Synapse Demo (synapseretention.com) sent an email with 9 problems. The most costly first.

“Black Friday early access: 20% off everything”

Campaign · arrived Fri 9 Oct at 20:23 Vienna time · to 2 of our addresses

  1. Proof it's from you

    This email from synapseretention.com failed the check that proves it really came from you. Gmail says mail that breaks its rules may not arrive, or may land in spam.

    Sent from
    demo@synapseretention.com

    What to do: Turn on a branded sending domain: it proves emails come from your web address.

  2. Subject and code disagree

    The subject line says 20% off, but the code TAKE15 gives 15% off.

    Subject line
    “Black Friday early access: 20% off everything”
    In the email
    “Use code TAKE15 for 15% off your first order.”

    What to do: Make the subject line and the code give the same discount. Otherwise a subscriber who opens for 20% is given a code for 15%.

    Only in the copy to our address without a first name.

  3. Subject and email disagree

    The subject line says 20% off, but the email says 15% off.

    Subject line
    “Black Friday early access: 20% off everything”
    In the email
    “Take 15% off your first order.”

    What to do: Make the subject line and the email give the same discount.

    Only in the copy to our address with a first name.

  4. One code, two discounts

    The code DOUBLE10 is given two different discounts in one email: 10% off and 25% off.

    In one place
    “Use code DOUBLE10 for 10% off.”
    In another
    “Code DOUBLE10 takes 25% off everything.”

    What to do: Give the code one discount everywhere, and check which one it takes at checkout.

  5. Discount links without a code

    The link “Shop early access” applies the code “CODE”, not a real code.

    The link
    “Shop early access”, which goes to https://synapseretention.com/discount/CODE

    What to do: Put the real code in the link, where it says CODE.

  6. Links that go nowhere

    The link “View this email in your browser” goes nowhere: it points to “*|ARCHIVE|*”. It's how Mailchimp writes a fill-in field, which your platform doesn't fill in.

    The link
    “View this email in your browser”, which goes to *|ARCHIVE|*

    What to do: Point it at your email platform's own “view in browser” link, or take it out.

  7. Links that may not open

    Some email apps may not open the link “See everything in early access”: no https:// at its start.

    The link
    “See everything in early access”, which goes to www.synapseretention.com/early-access

    What to do: Change it to https://www.synapseretention.com/early-access so every email app opens it.

  8. Text subscribers shouldn't see

    Subscribers see “*|FNAME|*” where their first name should be. It's how Mailchimp writes a fill-in field, which your platform doesn't fill in.

    In the email
    “*|FNAME|*, early access closes on Sunday.”

    What to do: Use your email platform's own first-name field, with “there” for people without a name.

  9. A greeting with no name

    The greeting reads “Hi ,” for subscribers who didn't give a first name.

    In the email
    “Hi ,”

    What to do: Give the name a fallback, like “there”, so it reads “Hi there,”.

    Only in the copy to our address without a first name.

Every check of every email, on synapseretention.com's page: https://portal.synapseretention.com/w/demo/domain/synapseretention.com

You get this because you're an owner or admin of Synapse Demo on Synapse Retention. We email you about a problem when it shows up, and not again while it stays on the page.

The alert is shown in the words our alerts use today. Its times and its nine problems are the test’s own.

The 16 seconds, as our records show them.

Friday 9 October 2026, Vienna time. One timed test, on our own account.

  1. Klaviyo sends our test campaign.

  2. We check the copy to our address without a first name. It has eight of the problems.

  3. We check the copy to our address with a first name. It has one more.

  4. The alert goes out, with all nine: 16 seconds after the campaign was sent.

We wait ten seconds after the last copy, so one campaign makes one alert. The ten mistakes we planted that day, and what caught each one, are below.

Ten planted mistakes. Ten caught.

On 9 October 2026 we tested our checks on our own Klaviyo account. We planted ten mistakes: nine in one campaign, one in an email from an ordinary mailbox. Our alerts named all ten.

  • Sent from our web address without a branded sending domain, so it fails the check that proves it’s us.

    Caught: no proof it’s from you

  • An email from an ordinary mailbox, with no one-click unsubscribe button.

    Caught: no one-click unsubscribe button

  • The subject says 20% off. The code TAKE15 gives 15%.

    Caught: the subject and the code disagree

  • The subject says 20% off. The email says 15%.

    Caught: the subject and the email disagree

  • One code, DOUBLE10, offered as 10% off and as 25% off.

    Caught: one code, two discounts

  • A “Shop early access” button that applies the code “CODE”.

    Caught: a discount link without its code

  • A “View this email in your browser” link that goes nowhere.

    Caught: a link that goes nowhere

  • A link to our own site with no https://, which some email apps may not open.

    Caught: a link some email apps may not open

  • “*|FNAME|*” left in the text: a fill-in field from another email tool.

    Caught: text subscribers shouldn’t see

  • A greeting that reads “Hi ,” for people who didn’t give a first name.

    Caught: a greeting with no name

See it on your own emails.

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Get early access hello@synapseretention.com
Issued by
Synapse Retention
Signed
Mohamed Hamed, FounderMohamed Belal, Co-founder
Based in
Budapest and London · working with US brands