Home > Empowering Tips > The Importance of SMTP Authentication in Mail Apps

If you use a mail app like Microsoft Outlook, Apple Mail, or a mobile email app to send emails, there’s an important setting you should never ignore:
“My outgoing server (SMTP) requires authentication.”

This small checkbox plays a big role in whether your emails are sent successfully — and whether they’re trusted by mail servers.

What Is SMTP Authentication?

SMTP (Simple Mail Transfer Protocol) is the system used to send emails.
SMTP authentication means your mail app must verify your identity before it is allowed to send emails.

When authentication is enabled, your email address and password are used to confirm that:

• You are authorised to send emails
• The server is not being misused by unauthorised users

This applies to all third-party mail apps, including desktop and mobile email clients.

Why SMTP Authentication Is Required

Modern email systems no longer allow unauthenticated email sending. This requirement exists to protect both email users and mail servers.

Prevents Spam and Abuse

Without authentication, anyone could send emails through a mail server. This would quickly lead to spam, phishing, and the server being blocked or blacklisted.

Protects Your Email Account and Domain

SMTP authentication helps ensure emails are genuinely sent by the account owner, reducing the risk of spoofed or forged emails using your address.

Improves Email Delivery

Receiving mail servers expect emails to be properly authenticated. Emails sent without SMTP authentication are more likely to be rejected or filtered into junk folders.

Why This Setting Must Be Enabled in Mail Apps

When setting up a mail app, users often focus on incoming email settings (IMAP or POP3) and overlook the outgoing server configuration.

However, our servers require SMTP authentication to be enabled in order to send emails from third-party applications.

If this option is not enabled, users may experience:

• Emails stuck in the Outbox
• Errors such as “Authentication required” or “Relay denied”
• Emails that appear sent but never reach the recipient

The Setting to Look For

Most mail apps include an outgoing mail setting related to SMTP authentication, although the wording may differ depending on the app you’re using.

You may see options such as:

• My outgoing server (SMTP) requires authentication
• Outgoing server requires authentication
• Use authentication when sending mail
• Authentication method: Password

While the labels may look different, they all serve the same purpose — confirming your identity before sending emails.

Once configured correctly, your mail app will be able to send emails securely and reliably.

Why This Matters for Everyday Email Users

Even if you’re not technical, SMTP authentication directly affects your daily email experience:

• Emails send without errors
• Messages are less likely to be blocked or filtered
• Your email account is protected from misuse
• Your recipients are more likely to receive your emails normally

In short, it’s a basic requirement for modern email usage.

Final Thoughts

The “SMTP requires authentication” option is not optional — it’s essential.

If you’re using a third-party mail app, make sure this setting is enabled. Our servers enforce SMTP authentication to ensure secure, reliable email sending for all users.

If you encounter issues sending emails, checking this setting should always be one of the first troubleshooting steps.

Frequently Asked Questions (FAQ)

Do I need SMTP authentication if I only send a few emails?

Yes. SMTP authentication is required regardless of how many emails you send. Even occasional emails must be authenticated to prevent misuse.

I can receive emails but can’t send. Is this related?

Very likely. Incoming emails use IMAP or POP3, while sending emails uses SMTP. If SMTP authentication is not enabled, sending will fail even though receiving works.

Can I disable SMTP authentication if my password is correct?

No. Passwords are part of SMTP authentication. If authentication is disabled, the server will reject the sending request, even if your password is correct.

Is SMTP authentication required for webmail?

Webmail handles authentication automatically. This requirement mainly applies when using third-party mail apps.

What should I do if emails are still not sending?

Double-check that:

• SMTP authentication is enabled
• The correct email address and password are used
• The outgoing server settings match the recommended configuration

If the issue persists, contact your IT support for further assistance.