Connect your existing application, framework or SMTP-compatible software to Sendzovo and send transactional email without rebuilding your existing mail integration.
SMTP, or Simple Mail Transfer Protocol, is the standard protocol used by applications and mail servers to send email across the internet.
SMTP defines how an email client or application connects to a mail server, authenticates, submits a message and transfers it for delivery.
When your application already supports SMTP, you can connect it to Sendzovo without replacing your existing email-sending implementation.
SMTP is supported by most programming languages, frameworks, CMS platforms and business applications. This makes it a practical way to connect existing software to an email delivery provider.
Sendzovo provides the email delivery infrastructure behind your SMTP connection so your application can focus on creating and sending messages.
Send password resets, account notifications, confirmations, receipts and other product-critical messages through your existing SMTP integration.
Authenticate your sending domain with the DNS records provided by Sendzovo before sending production email.
Monitor email delivery activity and use delivery events to build automated workflows around your messages.
Send delivery events back to your application so your systems can respond to email activity automatically.
Verify email addresses before sending to reduce invalid recipients and improve the quality of your sending lists.
Use SMTP for existing integrations and the Sendzovo Email API when you need a direct HTTP-based integration.
Your application uses an SMTP connection to submit an email to Sendzovo. Sendzovo then processes the message through its email delivery infrastructure.
Use these settings when configuring your application or SMTP-compatible software.
Port 587 uses STARTTLS to upgrade the SMTP connection to an encrypted connection.
Authenticate using the SMTP credentials associated with your Sendzovo account.
SMTP providers may support different connection modes. Use the configuration supported by your Sendzovo account and infrastructure.
Recommended: Use port 587 with STARTTLS for most applications and SMTP clients.
SMTP authentication is required using the credentials provided by your Sendzovo account.
Only use additional SMTP ports or encryption modes that Sendzovo explicitly provides for your account. Port 587 with STARTTLS is the recommended configuration shown in these examples.
If your application already supports SMTP, you can connect it to Sendzovo using your SMTP credentials and connection settings.
Keep your SMTP credentials in environment variables or your application's secure configuration system. Never commit credentials to source control.
Choose the integration method that best fits your application architecture.
Choose SMTP when your application already supports SMTP or when connecting existing software, frameworks, CMS platforms or business applications.
Choose the Email API when you're building a new integration and want a direct HTTP and JSON interface for sending messages.
Use the SMTP settings provided by Sendzovo with the framework or mail library you're already using.
MAIL_HOST=smtp.sendzovo.com
MAIL_PORT=587
MAIL_ENCRYPTION=tls
MAIL_USERNAME=YOUR_SENDZOVO_SMTP_USERNAME
MAIL_PASSWORD=YOUR_SENDZOVO_SMTP_PASSWORDuse Illuminate\Support\Facades\Mail;
Mail::raw('Welcome to our application!', function ($message) {
$message
->to('customer@example.com')
->subject('Welcome to our application');
});import nodemailer from 'nodemailer';
const transporter = nodemailer.createTransport({
host: 'smtp.sendzovo.com',
port: 587,
secure: false,
auth: {
user: process.env.SENDZOVO_SMTP_USERNAME,
pass: process.env.SENDZOVO_SMTP_PASSWORD
},
tls: {
minVersion: 'TLSv1.2'
}
});
await transporter.sendMail({
from: 'hello@example.com',
to: 'customer@example.com',
subject: 'Welcome to our application',
html: 'Welcome!
'
});import os
import smtplib
from email.message import EmailMessage
message = EmailMessage()
message['From'] = 'hello@example.com'
message['To'] = 'customer@example.com'
message['Subject'] = 'Welcome to our application'
message.set_content('Welcome to our application!')
with smtplib.SMTP('smtp.sendzovo.com', 587) as smtp:
smtp.starttls()
smtp.login(
os.environ['SENDZOVO_SMTP_USERNAME'],
os.environ['SENDZOVO_SMTP_PASSWORD']
)
smtp.send_message(message)# settings.py
EMAIL_HOST = 'smtp.sendzovo.com'
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = os.environ['SENDZOVO_SMTP_USERNAME']
EMAIL_HOST_PASSWORD = os.environ['SENDZOVO_SMTP_PASSWORD']
# views.py
from django.core.mail import send_mail
send_mail(
'Welcome to our application',
'Welcome to our application!',
'hello@example.com',
['customer@example.com'],
)use PHPMailer\PHPMailer\PHPMailer;
$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host = 'smtp.sendzovo.com';
$mail->Port = 587;
$mail->SMTPAuth = true;
$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
$mail->Username = getenv('SENDZOVO_SMTP_USERNAME');
$mail->Password = getenv('SENDZOVO_SMTP_PASSWORD');
$mail->setFrom(
'hello@example.com',
'Example Application'
);
$mail->addAddress('customer@example.com');
$mail->Subject = 'Welcome to our application';
$mail->Body = 'Welcome to our application!';
$mail->send();using System.Net;
using System.Net.Mail;
using var client = new SmtpClient(
"smtp.sendzovo.com",
587
);
client.EnableSsl = true;
client.Credentials = new NetworkCredential(
Environment.GetEnvironmentVariable(
"SENDZOVO_SMTP_USERNAME"
),
Environment.GetEnvironmentVariable(
"SENDZOVO_SMTP_PASSWORD"
)
);
var message = new MailMessage(
"hello@example.com",
"customer@example.com"
);
message.Subject = "Welcome to our application";
message.Body = "Welcome to our application!";
await client.SendMailAsync(message);Properties props = new Properties();
props.put(
"mail.smtp.host",
"smtp.sendzovo.com"
);
props.put(
"mail.smtp.port",
"587"
);
props.put(
"mail.smtp.auth",
"true"
);
props.put(
"mail.smtp.starttls.enable",
"true"
);
Session session = Session.getInstance(
props,
new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(
System.getenv("SENDZOVO_SMTP_USERNAME"),
System.getenv("SENDZOVO_SMTP_PASSWORD")
);
}
}
);Connect Sendzovo to applications and platforms that already support standard SMTP configuration.
Configure Laravel's mail system or a PHP mail library to deliver application messages through Sendzovo.
Connect SMTP-compatible Node.js mail libraries and applications to Sendzovo.
Use Sendzovo as the SMTP backend for applications built with Python and Django.
Configure SMTP-compatible .NET applications to send transactional email through Sendzovo.
Connect Java applications and mail libraries using standard SMTP configuration.
Configure WordPress SMTP-compatible plugins and applications to send email through Sendzovo.
Deliver order confirmations, payment notifications and other WooCommerce transactional messages through Sendzovo SMTP.
If your application supports standard SMTP settings, you can configure it to use Sendzovo.
WordPress sites can use Sendzovo as their SMTP delivery provider through an SMTP-compatible mail plugin.
Use your Sendzovo SMTP username and password.
Use Sendzovo SMTP to deliver transactional messages generated by WooCommerce and your WordPress store.
Deliver order confirmation and purchase-related messages to customers.
Send payment and transaction-related notifications through your configured SMTP connection.
Deliver notifications when orders move through different stages of your store workflow.
Send account, password reset and other customer notifications through Sendzovo.
Use Sendzovo SMTP for application and business messages that need reliable email delivery.
Email verification, password resets, login alerts and account security notifications.
Order confirmations, receipts, invoices and payment notifications.
Product updates, system alerts, usage notifications and workflow messages.
Contact notifications, internal alerts and other application-generated business messages.
Configure your sending domain before sending production email through Sendzovo. Domain authentication helps receiving mail systems verify that your messages are authorized.
Publish the required SPF record to authorize the appropriate sending infrastructure for your domain.
Configure DKIM records provided by Sendzovo so outgoing messages can be cryptographically authenticated.
Configure a DMARC policy to define how receiving systems should handle authentication failures and help protect your domain from spoofing.
Send application messages using sender addresses associated with your authenticated sending domain.
Combine email verification with transactional email to validate addresses before sending messages to them.
Validate addresses before attempting to send messages to reduce avoidable delivery failures.
Keeping invalid and risky addresses out of your sending workflow can help maintain healthier recipient data.
Not every email can be delivered. Sendzovo can help your application understand delivery outcomes and respond to failed delivery attempts.
Permanent delivery failures such as invalid or non-existent recipient addresses.
Temporary delivery problems such as temporary mailbox or receiving-server issues.
Messages may be rejected because of recipient, authentication, policy or other delivery conditions.
Use delivery events to update your application, monitor message status and trigger automated workflows.
Keep problematic recipients from repeatedly entering your email delivery workflow.
Track recipients associated with permanent delivery failures.
Record complaint-related events and prevent unwanted future sending where appropriate.
Respect unsubscribe and suppression requirements in your application workflows.
Suppress specific recipients when your application or operational workflow requires it.
SMTP is only the beginning. Monitor what happens to your messages after they are submitted to Sendzovo.
Understand the current state of your email messages throughout the delivery lifecycle.
Review message activity and delivery events to help troubleshoot application email.
SMTP handles message submission while Sendzovo webhooks can notify your application about email events.
Configure your sender identity and authenticated sending domain before sending production email.
Use sender addresses associated with your verified sending domain.
Maintain a consistent sender identity across your application's transactional email.
Sendzovo SMTP works with standard email formats supported by your application and SMTP library.
Send HTML-formatted transactional messages for application notifications and customer communication.
Send lightweight plain-text messages when HTML email is unnecessary.
Use standard SMTP MIME attachments where supported by your application and Sendzovo configuration.
Configure recipients, CC and BCC through your existing SMTP-compatible mail library.
Message and attachment size limits depend on your Sendzovo configuration and account limits. Check your account documentation before sending large messages.
SMTP credentials provide access to your sending infrastructure and should be treated like application secrets.
Store credentials outside your source code and inject them through your application's environment.
Use the TLS-enabled SMTP configuration when connecting your application to Sendzovo.
Do not place SMTP usernames, passwords or other credentials directly into public repositories.
Replace compromised or exposed credentials promptly and update your application's configuration.
Never expose SMTP credentials in browser JavaScript, frontend applications or publicly accessible client code.
Give SMTP credentials only to the applications and services that need them.
Sending limits help protect your account and email infrastructure. Your actual limits may depend on your Sendzovo plan and account configuration.
SMTP sending may be subject to rate limits based on your account and sending configuration.
SMTP connections may be limited to protect the delivery infrastructure.
Messages and attachments may have maximum size requirements.
Your plan may determine the amount of email you can send during a billing period.
Check your Sendzovo plan and account documentation for the current limits that apply to your account.
You can test whether your server can establish a STARTTLS connection to the Sendzovo SMTP endpoint.
openssl s_client -starttls smtp -connect smtp.sendzovo.com:587telnet smtp.sendzovo.com 587If the connection fails, check your server firewall, hosting provider restrictions, DNS configuration and outbound SMTP access.
Most SMTP connection problems come down to incorrect credentials, connection settings, TLS configuration or network restrictions.
Verify that your SMTP username and password are correct and that the credentials belong to the intended Sendzovo account.
Check your server firewall and hosting provider's outbound SMTP restrictions.
Verify the SMTP hostname and port and make sure your server can establish outbound connections to the Sendzovo SMTP service.
Verify that your application is configured to use STARTTLS on the supported SMTP port.
Make sure the sender address belongs to a configured and authenticated sending domain.
Review the SMTP response and Sendzovo message logs to determine why the message was rejected.
Check your sending rate and account limits before retrying the message.
Check the message's delivery status and bounce event to determine whether the recipient address or receiving server caused the failure.
Follow this checklist before sending transactional email from your production application.
Sendzovo fits into your existing application's email workflow without requiring you to build your own SMTP delivery infrastructure.
Common questions about connecting applications to Sendzovo SMTP.
Yes. Applications and software that support standard SMTP configuration can be configured to send email through Sendzovo.
Port 587 with STARTTLS is the recommended configuration for most applications.
You should authenticate your sending domain before sending production email. This can include SPF, DKIM and DMARC configuration.
Yes. Laravel applications can use Sendzovo through Laravel's SMTP mail configuration.
Yes. WordPress installations can use Sendzovo through SMTP-compatible mail configuration.
Yes. SMTP and the Email API are different integration methods. You can choose the method that best fits each application or integration.
Yes. SMTP supports standard HTML email messages when your application or mail library generates HTML email.
No. SMTP credentials should remain server-side and should be stored securely using environment variables or your application's secret-management system.
Already sending email through SMTP? Update your SMTP configuration and start using Sendzovo for your transactional email workflow.
Go beyond SMTP with tools for transactional email, verification, delivery and email management.
Send transactional email through a REST API built for modern applications.
Explore Email API →Send password resets, notifications, confirmations and other product-critical messages.
Explore Transactional Email →Verify addresses before sending to reduce invalid and risky email addresses.
Explore Email Verification →Authenticate your sending domains using DNS-based email authentication.
Explore Domain Authentication →Receive email delivery events in your application and build automated workflows.
Explore Webhooks →Separate transactional and bulk email traffic into dedicated streams for better organization and control.
This feature is currently under development.