Email app error “Relay access denied” / “Authentication required” (SMTP): how to fix (GARMTECH)

If your email app cannot send messages and shows errors like:

• 550 5.7.1 Relay access denied
• Authentication required
• SMTP error: Could not authenticate

…the app is usually trying to send mail without SMTP authentication, or it is using the wrong outgoing server.

Step 1 — Use the correct SMTP server

For GARMTECH mail services, the safest option is to use the service server hostname shown in My.GARMTECH service details.

• Do not use a random hostname like smtp.yourdomain.com unless you configured it in DNS and it resolves to the correct server.
• If you have multiple services (Hosting Email + Business Email), make sure you use the hostname for the mailbox you are configuring.

Step 2 — Check the SMTP port and encryption

Recommended outgoing mail settings:

• Port: 465
• Encryption: SSL (sometimes called “SSL/TLS”)

Step 3 — Enable “My outgoing server requires authentication”

Many clients (Outlook, Apple Mail, mobile apps) have a separate checkbox for SMTP authentication. Enable it and use the same login as for IMAP:

• Username: full email address (for example, you@example.com)
• Password: mailbox password

Step 4 — If you use 2FA, use an app password

If two-factor authentication is enabled for your mailbox, regular passwords may be blocked for mail apps. Create an app password and use it as the SMTP password.

Step 5 — Confirm the “From” address matches the mailbox

• Make sure you are sending “From” the same address you authenticated with.
• Sending as another address requires proper “Send as” permissions or aliases on the server side.

Additional checks

• If your email app has an option like “Use same settings as my incoming mail server”, enable it (it often turns on authentication automatically).
• Make sure the username is the full email address (you@example.com), not just “you”.
• If you recently changed the password, update it on all devices too (otherwise repeated failed attempts may get blocked).

Common quick fixes

• Re-enter the password (copy/paste can include extra spaces).
• Remove and re-add the account in the mail app if settings are mixed up.
• Test with a different network if your ISP blocks outgoing SMTP (rare when using port 465 SSL, but possible).