Fixing “Can’t Send Email” After Our TLS Security Update

Starting September 1, 2026, our mail servers require a secure (TLS-encrypted) connection before accepting login credentials. If your email suddenly stopped sending, this guide will get you back up and running.

The fix in one sentence: Set your outgoing (SMTP) mail server to mail.superb.net or mail.yourdomain.com, using port 587 or port 465, with TLS/SSL encryption.

Quick Settings Reference

Setting Value
Outgoing server (SMTP) mail.superb.net or mail.yourdomain.com
Port 587 (TLS/STARTTLS) or 465 (SSL/TLS)
Encryption TLS (STARTTLS on 587) or SSL/TLS (implicit, on 465)
Authentication Required — use your normal email username and password

Instructions by Email Client

Outlook (Desktop — Windows/Mac)

  1. Go to File > Account Settings > Account Settings.
  2. Select your email account and click Change.
  3. Click More Settings > Advanced.
  4. Set Outgoing server (SMTP) to mail.superb.net (or mail.yourdomain.com), port 587 or 465, encryption type TLS/SSL.
  5. Confirm “My outgoing server requires authentication” is checked.
  6. Click OK, then Next to test the account.

Outlook (Web / Microsoft 365)

Outlook on the web uses Microsoft’s servers, not ours, so no changes are needed there. This applies only if you’re sending through our SMTP server from a desktop client, mobile app, or another connected app/device.

Apple Mail (Mac)

  1. Open Mail > Settings (or Preferences) > Accounts.
  2. Select your account, then go to Server Settings.
  3. Under Outgoing Mail Server (SMTP), click Edit SMTP Server List.
  4. Uncheck “Automatically manage connection settings.”
  5. Set Server Name to mail.superb.net or mail.yourdomain.com, Port to 587 or 465, and enable Use TLS.
  6. Enter your username and password if prompted, then save.

Apple Mail (iPhone/iPad)

  1. Go to Settings > Mail > Accounts and select your account.
  2. Tap your account name, then SMTP under Outgoing Mail Server.
  3. Tap your primary server, and set:
    • Host Name: mail.superb.net or mail.yourdomain.com
    • Server Port: 587 or 465
    • Use SSL: On (enables encrypted TLS on either port)
  4. Save and exit.

Mozilla Thunderbird

  1. Go to Tools > Account Settings (or the hamburger menu > Account Settings).
  2. Select Outgoing Server (SMTP) in the left panel.
  3. Select your server and click Edit.
  4. Set Server Name to mail.superb.net or mail.yourdomain.com, Port to 587 or 465, Connection security to STARTTLS (port 587) or SSL/TLS (port 465).
  5. Set Authentication method to Normal password (or as previously configured).
  6. Click OK to save.

Gmail App / Android Mail App (connecting a non-Gmail account)

  1. Open the Gmail app > Settings > select the account.
  2. Tap Outgoing server settings (or similar, depending on app version).
  3. Set the server to mail.superb.net or mail.yourdomain.com, Port to 587 or 465, and ensure Require TLS is enabled.
  4. Save changes.

Generic / Other Mail Apps

Look for a section labeled Outgoing Mail Server, SMTP Settings, or Server Settings. You’re looking for four things:

  • Server: mail.superb.net or mail.yourdomain.com
  • Port: 587 or 465
  • Encryption / Security type: TLS — not “None”
  • Authentication: make sure it’s still enabled with your normal login

Scanners, Printers, and Other Devices (“Scan to Email”)

  1. Log into the device’s web admin panel (usually via its IP address in a browser).
  2. Find the Email or SMTP configuration section.
  3. Set the server to mail.superb.net or mail.yourdomain.com, update the port to 587 or 465, and enable TLS/SSL.
  4. Save and send a test scan/email.
  5. If the device’s firmware doesn’t offer a TLS option at all, contact us — older devices sometimes need a firmware update, or we can help find another way to route mail from it.

Automated Systems, Monitoring Tools, and Application Integrations

Any software or device that sends email automatically (billing systems, alerting/monitoring tools, CRM integrations, etc.) needs the same update in its own SMTP configuration screen. These are the most commonly missed, since they’re often set up once and forgotten. If you’re not sure where this is configured, check with whoever set up the integration, or contact us for help identifying it.

Common Problems & Fixes

“My email suddenly stopped sending / authentication failed”

Cause: Your client is still using an unencrypted connection, which is no longer accepted.

Fix: Update the server and encryption settings as described above (mail.superb.net or mail.yourdomain.com, port 587 or 465, with TLS/SSL enabled). Also confirm you’re not still using port 25 for sending — that port is for server-to-server mail relay, not for sending from your personal client.

No TLS option available, or the setting is greyed out

Cause: An outdated mail app, or a device/OS that doesn’t support modern TLS.

Fix: Update the mail app or device’s operating system to the latest available version. If webmail works fine but the desktop/mobile app doesn’t, the issue is isolated to that app — try reinstalling it or checking for updates.

“Certificate not trusted” or SSL warning appears when enabling TLS

Cause: You may be connecting to the wrong server address (like a raw IP address instead of the hostname), or your device’s trusted certificate list is out of date.

Fix: Double-check the outgoing server is set to mail.superb.net or mail.yourdomain.com — not an IP address. If the certificate is valid and current but still flagged, update your device’s OS/trust store.

Works on one Wi-Fi network but not another (e.g., office or hotel Wi-Fi)

Cause: Some networks block outbound port 587 or 465, or intercept encrypted traffic.

Fix: Try the other supported port (465 if 587 doesn’t work, or vice versa). If neither works, check with that network’s administrator about outbound mail port restrictions.

A shared mailbox, printer, scanner, or automated tool stopped sending

Cause: Devices and automated integrations are often configured once and never revisited, so they’re the most likely to still be using the old, unencrypted method.

Fix: Locate the SMTP settings in the device or application’s admin panel and update them the same way as a personal email client. If the device is old enough that it has no TLS option at all, contact support for help finding another solution.

Do I need to change my Authentication method too?

Cause: Some devices (like iPhone) show an Authentication method dropdown — Password, MD5 Challenge-Response, NTLM, HTTP MD5 Digest — near the port and SSL settings, which can make it look related.

Fix: No — leave Authentication set to Password. That setting controls how your login credentials are packaged, which is separate from the port/encryption change. Both port 465 (implicit SSL/TLS) and port 587 (TLS via STARTTLS) encrypt the connection before your login credentials are sent, so either is fully supported — you don’t need to switch ports if 465 with SSL/TLS is already working for you.

Multiple mailboxes route through one shared server/relay

Cause: Some office setups relay all outgoing mail through a single local server or PBX/scan system.

Fix: Update the TLS settings once on that shared relay/service account — this typically fixes it for everyone using it.

Still Stuck? Contact Support

Support Portal https://mycp.superb.net
Phone 888.354.6128

When you reach out, please include:

  • The name of your email app or device
  • The version of your email app or device
  • The error message you’re seeing (if any)
  • Whether it worked before and recently stopped

We’re happy to walk through the settings with you directly.