{"id":996,"date":"2026-09-08T06:22:19","date_gmt":"2026-09-08T06:22:19","guid":{"rendered":"https:\/\/smppcenter.com\/kb\/?p=996"},"modified":"2026-09-08T06:22:22","modified_gmt":"2026-09-08T06:22:22","slug":"how-to-set-up-smtp-in-smpp-center","status":"publish","type":"post","link":"https:\/\/smppcenter.com\/kb\/how-to-set-up-smtp-in-smpp-center\/","title":{"rendered":"How to Set Up SMTP in SMPP Center"},"content":{"rendered":"\n

SMTP is how SMPP Center sends emails from your platform: login alerts, OTP, password reset, credit notifications, support tickets, invoices, and bulk or marketing email. This guide covers platform SMTP (Admin), reseller SMTP (White Label), testing the connection, provider profiles for bulk email, and common fixes.<\/p>\n\n\n\n

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Why SMTP Matters<\/h2>\n\n\n\n
Mailer Type<\/th>What it does<\/th>When to use<\/th><\/tr><\/thead>
PHP Mail<\/strong> (not recommended<\/strong>)<\/td>Uses the server\u2019s built-in mail function<\/td>Quick tests only. Limited reliability. Attachments are not supported.<\/strong><\/td><\/tr>
SMTP<\/strong> (Recommended)<\/strong><\/td>Connects to your mail provider (Gmail, Google Workspace, Microsoft 365, Amazon SES, SendGrid, Mailgun, cPanel mail, etc.)<\/td>Recommended for production.<\/strong> Required for attachments and reliable delivery.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Always use SMTP<\/strong> in production.<\/p>\n\n\n\n

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What Gets Sent Over SMTP<\/h2>\n\n\n\n

Once SMTP is configured correctly, the platform can send:<\/p>\n\n\n\n

    \n
  • Admin and user login alerts<\/li>\n\n\n\n
  • Welcome emails and password reset links<\/li>\n\n\n\n
  • Login \/ signup OTP emails<\/li>\n\n\n\n
  • Credit add or remove notifications<\/li>\n\n\n\n
  • Sender ID and support ticket emails<\/li>\n\n\n\n
  • Rate \/ price notification emails (optional separate SMTP)<\/li>\n\n\n\n
  • Marketing and bulk email campaigns<\/li>\n\n\n\n
  • Postpaid invoices and expiry \/ low-balance reminders<\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n

    Part 1: Platform SMTP (Admin Panel)<\/h2>\n\n\n\n

    Use this for the main platform email identity and for the root\/admin account mail flow.<\/p>\n\n\n\n

    Step 1: Open E-Mail Settings<\/h3>\n\n\n\n
      \n
    1. Log in to the Admin Panel<\/strong>.<\/li>\n\n\n\n
    2. Go to Settings \u2192 General<\/strong>.<\/li>\n\n\n\n
    3. Open the E-Mail Settings<\/strong> tab.<\/li>\n<\/ol>\n\n\n\n

      You will see sections for:<\/p>\n\n\n\n

        \n
      • Email branding (logo, footer, copyright, unsubscribe text)<\/li>\n\n\n\n
      • E-Mail \u2013 SMTP Settings<\/strong><\/li>\n\n\n\n
      • Marketing batch mail options<\/li>\n\n\n\n
      • Bulk E-Mail Dispatch \u2013 SMTP Provider Profile<\/strong><\/li>\n<\/ul>\n\n\n\n

        Step 2: Set Mailer Type to SMTP<\/h3>\n\n\n\n
          \n
        1. Find Mailer Type<\/strong>.<\/li>\n\n\n\n
        2. Select SMTP<\/strong>.<\/li>\n\n\n\n
        3. The SMTP fields appear.<\/li>\n<\/ol>\n\n\n\n

          Note shown in the panel:<\/strong> SMTP must be enabled if you want to send attachments<\/strong> in email.<\/p>\n\n\n\n

          Step 3: Fill SMTP Connection Fields<\/h3>\n\n\n\n
          Field<\/th>Required<\/th>What to enter<\/th><\/tr><\/thead>
          SMTP Host<\/strong><\/td>Yes<\/td>Your provider host, e.g. smtp.gmail.com<\/code>, smtp.office365.com<\/code>, email-smtp.ap-south-1.amazonaws.com<\/code>, or mail.yourdomain.com<\/code><\/td><\/tr>
          SMTP Encryption<\/strong><\/td>Yes<\/td>SSL<\/strong> or STARTTLS<\/strong><\/td><\/tr>
          SMTP Port<\/strong><\/td>Yes<\/td>Usually 465<\/strong> for SSL, 587<\/strong> for STARTTLS (the UI often auto-fills this when you change encryption)<\/td><\/tr>
          From Name<\/strong><\/td>Yes<\/td>Display name recipients see, e.g. SMPP Center Alerts<\/code><\/td><\/tr>
          SMTP Username<\/strong><\/td>Optional*<\/td>Leave blank for Gmail \/ most providers (From E-Mail is used). For AWS SES<\/strong>, enter the SMTP username starting with AKIA...<\/code><\/td><\/tr>
          From E-Mail<\/strong><\/td>Yes<\/td>A verified sender address<\/strong>, e.g. noreply@yourdomain.com<\/code>. Never put an AWS AKIA...<\/code> username here<\/td><\/tr>
          Reply-To E-Mail<\/strong><\/td>Optional<\/td>Where replies should go. Leave blank to use the From address<\/td><\/tr>
          SMTP Auth Mode<\/strong><\/td>Optional<\/td>Leave Default (automatic)<\/strong> unless your provider requires LOGIN, PLAIN, or CRAM-MD5<\/td><\/tr>
          SMTP Password<\/strong><\/td>Yes<\/td>Mailbox password or app password \/ SMTP secret<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

          *AWS SES and some enterprise relays require Username.<\/p>\n\n\n\n

          Step 4: Set Admin Notification Address<\/h3>\n\n\n\n

          On the General settings area (same Settings page), confirm:<\/p>\n\n\n\n

            \n
          • Admin Notification E-Mail<\/strong> \u2013 where test mail and admin alerts are delivered (comma-separated for multiple)<\/li>\n\n\n\n
          • Site E-Mail (MAIL FROM)<\/strong> \u2013 platform identity used in some notification flows<\/li>\n<\/ul>\n\n\n\n

            The Test Connection<\/strong> feature sends the test message to your Admin Notification E-Mail.<\/p>\n\n\n\n

            Step 5: Test Connection<\/h3>\n\n\n\n
              \n
            1. Click Test Connection<\/strong>.<\/li>\n\n\n\n
            2. Wait for the result.<\/li>\n\n\n\n
            3. Success shows: SMTP Connected<\/strong><\/li>\n\n\n\n
            4. Check the Admin Notification inbox (and spam folder) for a Test Mail<\/strong> message.<\/li>\n<\/ol>\n\n\n\n

              If the test fails, fix credentials or network access first. Do not assume Save alone means mail will work.<\/p>\n\n\n\n

              Step 6: Save Settings<\/h3>\n\n\n\n

              Click Save<\/strong> on General settings so host, encryption, port, From details, and password are stored. The password is stored encrypted.<\/p>\n\n\n\n

              \n\n\n\n

              Part 2: Reseller SMTP (White Label)<\/h2>\n\n\n\n

              Resellers who send their own branded emails need their own SMTP under White Label. Without this, reseller bulk email and many reseller-branded notifications will not send correctly.<\/p>\n\n\n\n

              Path A: Reseller configures their own SMTP<\/h3>\n\n\n\n
                \n
              1. Log in to the Reseller \/ User Panel<\/strong>.<\/li>\n\n\n\n
              2. Open White Label<\/strong>.<\/li>\n\n\n\n
              3. Go to the Email category.<\/li>\n\n\n\n
              4. Open SMTP Connectivity<\/strong>.<\/li>\n\n\n\n
              5. Fill the same style of fields as Admin SMTP (Host, Encryption, Port, From Name, Username, From E-Mail, Password, optional Reply-To and Auth Mode).<\/li>\n\n\n\n
              6. Optionally set an SMTP Provider Profile<\/strong> for bulk dispatch (see Part 4).<\/li>\n\n\n\n
              7. Click Test Connection<\/strong>.<\/li>\n\n\n\n
              8. On success (SMTP Connected<\/strong>), Save<\/strong>.<\/li>\n<\/ol>\n\n\n\n

                If SMTP Connectivity is missing, sending email from the reseller panel typically shows a message asking you to configure and save SMTP under White Label first.<\/p>\n\n\n\n

                Path B: Admin configures SMTP for a reseller<\/h3>\n\n\n\n
                  \n
                1. Admin Panel \u2192 Users<\/strong> \u2192 edit the reseller.<\/li>\n\n\n\n
                2. Open the Reseller<\/strong> tab.<\/li>\n\n\n\n
                3. Find Reseller SMTP Settings<\/strong>.<\/li>\n\n\n\n
                4. Enter host and related fields.<\/li>\n\n\n\n
                5. Leave Password blank<\/strong> on update if you want to keep the existing password.<\/li>\n\n\n\n
                6. Use Test Connection<\/strong>, then save the user.<\/li>\n<\/ol>\n\n\n\n

                  These values are stored the same way as White Label SMTP Connectivity.<\/p>\n\n\n\n

                  Optional: Rate Notification SMTP<\/h3>\n\n\n\n

                  Under White Label you may also see Rate Notification SMTP<\/strong>. Use a separate mailbox if price\/rate emails should go out from a different From address than general alerts. If it is not set, the default SMTP Connectivity is used.<\/p>\n\n\n\n

                  \n\n\n\n

                  Part 3: Encryption and Port Cheat Sheet<\/h2>\n\n\n\n
                  Encryption<\/th>Typical port<\/th>Common providers<\/th><\/tr><\/thead>
                  SSL<\/strong><\/td>465<\/strong><\/td>Many cPanel \/ hosting SMTP setups<\/td><\/tr>
                  STARTTLS<\/strong><\/td>587<\/strong><\/td>Gmail, Google Workspace, Microsoft 365, many transactional providers<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

                  Tips:<\/p>\n\n\n\n

                    \n
                  • Prefer 587 + STARTTLS or 465 + SSL as your provider documents.<\/li>\n\n\n\n
                  • Port 25 is often blocked by cloud hosts. Avoid it unless your provider explicitly requires it and the server allows outbound 25.<\/li>\n\n\n\n
                  • Firewall \/ security groups must allow outbound TCP to your SMTP host on the chosen port.<\/li>\n<\/ul>\n\n\n\n
                    \n\n\n\n

                    Part 4: SMTP Provider Profile (Bulk \/ Marketing Email)<\/h2>\n\n\n\n

                    This is not<\/strong> a second SMTP account. It controls how fast<\/strong> bulk email is dispatched so you stay within provider limits and avoid temporary blocks.<\/p>\n\n\n\n

                    Where to set it<\/h3>\n\n\n\n
                      \n
                    • Admin:<\/strong> Settings \u2192 General \u2192 E-Mail Settings \u2192 Bulk E-Mail Dispatch \u2013 SMTP Provider Profile<\/li>\n\n\n\n
                    • Reseller:<\/strong> White Label \u2192 SMTP Connectivity \u2192 Bulk E-Mail Dispatch Settings \u2013 SMTP Provider Profile<\/li>\n<\/ul>\n\n\n\n

                      Profile options<\/h3>\n\n\n\n
                      Profile<\/th>Rough pacing<\/th>Best for<\/th><\/tr><\/thead>
                      Google Workspace (Safe)<\/strong><\/td>About 20 emails\/min<\/td>Gmail \/ Google Workspace<\/td><\/tr>
                      Standard<\/strong><\/td>About 120 emails\/min<\/td>Most shared \/ business SMTP<\/td><\/tr>
                      High Volume<\/strong><\/td>About 600 emails\/min<\/td>SendGrid, Mailgun, Amazon SES, similar<\/td><\/tr>
                      Enterprise<\/strong><\/td>About 1200 emails\/min<\/td>Dedicated high-capacity relays<\/td><\/tr>
                      Custom<\/strong><\/td>You set batch size, rate, and reconnect interval<\/td>Advanced tuning<\/td><\/tr>
                      Use platform default<\/strong> (reseller)<\/td>Falls back to admin settings, then safe defaults<\/td>When unsure<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

                      If you leave profile unset, the platform can auto-detect from the SMTP host (for example Google\/Outlook-style hosts use a safer profile; SendGrid\/Mailgun\/SES-style hosts use higher volume).<\/p>\n\n\n\n

                      Marketing batch settings (Admin)<\/h3>\n\n\n\n

                      Also configure:<\/p>\n\n\n\n