cURL
curl -X POST https://cloudapi.mailercloud.com/v1/transactional-email/suppressions \
-H "Authorization: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"emails": ["one@example.com", "two@example.com"]}'import requests
url = "https://cloudapi.mailercloud.com/v1/transactional-email/suppressions"
payload = { "emails": ["one@example.com", "two@example.com"] }
headers = {
"Authorization": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({emails: ['one@example.com', 'two@example.com']})
};
fetch('https://cloudapi.mailercloud.com/v1/transactional-email/suppressions', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://cloudapi.mailercloud.com/v1/transactional-email/suppressions",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'emails' => [
'one@example.com',
'two@example.com'
]
]),
CURLOPT_HTTPHEADER => [
"Authorization: <api-key>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://cloudapi.mailercloud.com/v1/transactional-email/suppressions"
payload := strings.NewReader("{\n \"emails\": [\n \"one@example.com\",\n \"two@example.com\"\n ]\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}{
"added": 1,
"skipped": 1,
"duplicates": 0,
"data": [
{
"email": "one@example.com",
"reason": "manual",
"source": "api",
"smtp_response": "",
"date_added": 1787204050,
"date_added_local": "2026-08-19 05:34:10"
}
]
}Add Suppressions
Adds one or more recipients to your suppression list. They are rejected on every future send until reactivated.
The request is all-or-nothing: if any address is not a valid email address the whole request is rejected and the offending values are named, so a typo cannot leave you believing an address is suppressed when it is not.
Sample Code
POST
/
v1
/
transactional-email
/
suppressions
cURL
curl -X POST https://cloudapi.mailercloud.com/v1/transactional-email/suppressions \
-H "Authorization: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"emails": ["one@example.com", "two@example.com"]}'import requests
url = "https://cloudapi.mailercloud.com/v1/transactional-email/suppressions"
payload = { "emails": ["one@example.com", "two@example.com"] }
headers = {
"Authorization": "<api-key>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
body: JSON.stringify({emails: ['one@example.com', 'two@example.com']})
};
fetch('https://cloudapi.mailercloud.com/v1/transactional-email/suppressions', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://cloudapi.mailercloud.com/v1/transactional-email/suppressions",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'emails' => [
'one@example.com',
'two@example.com'
]
]),
CURLOPT_HTTPHEADER => [
"Authorization: <api-key>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://cloudapi.mailercloud.com/v1/transactional-email/suppressions"
payload := strings.NewReader("{\n \"emails\": [\n \"one@example.com\",\n \"two@example.com\"\n ]\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "<api-key>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}{
"added": 1,
"skipped": 1,
"duplicates": 0,
"data": [
{
"email": "one@example.com",
"reason": "manual",
"source": "api",
"smtp_response": "",
"date_added": 1787204050,
"date_added_local": "2026-08-19 05:34:10"
}
]
}Authorizations
Your Mailercloud API key (plain text, no Bearer prefix). Create keys in Settings → API.
Body
application/json
The addresses to suppress.
Example:
["one@example.com", "two@example.com"]
⌘I