Before we go ahead to explain how this can be fixed, you first need to understand why you are seeing it. Today, we’ve seen the top reasons for the error and how our Support Engineers fix it.While trying to access a website, you are faced with an error page that says, “Your connection is not secure”. SMTP: STARTTLS failed is an error that happens when using mail functionality in various applications. Therefore, our Security Engineers set up mail server with valid SSL certificate that matches the server name.Īdditionally, when server uses PEAR packages, we ensure that the module Net_SMTP do support TLS too. Last, but not the least, proper SSL certificate for the mail server is also needed for mail to work. To fix the problem, we had to reload the firewall. It was blocking access to port 587 of the mail server. On a detailed check, our Support Engineers found that the server firewall was causing the issue here. From our side, we checked and confirmed that the versions of PHP was fine too. Here, customer confirmed that he did not do any modifications in the mail script. Similarly, another customer started receiving this error, soon after a server reboot. The same fix was applicable when a customer reported problem with osTicket help-desk too. This fixed the problem and the mail started working.
We check and correct the typos in the mail server name, username, password etc.įor example, when one of customers reported “ SMTP: STARTTLS failed” error in their mail app, our Support Engineers had to put “ ssl://” in front of the SMTP server name. This gives us a clue on the exact settings that create problems.Īnd, the fixes vary according to the cause.įirstly, we check and verify the SMTP settings used in the app. When customers report problems with mail functionality, we first check the mail server logs. So far, we saw the various reasons for the SMTP: STARTTLS failed error. Here, the mails from the website form failed with the error: Authentication failure Recently, in one of the servers, the reason for error sending mail was port 587 blocked in the firewall. Port restrictions in the server firewall can also cause this error.
This made PHP’s verification to fail and report error.Īgain, the error can pop up when the SMTP server name is wrongly configured in the application as well. Recently, we saw this error when the server was sending the SMTP EHLO command as “localhost” instead of the real hostname. Yet another reason for the STARTTLS failed error can be bad configuration of the mail aka SMTP server. Therefore, it is a requirement that the certificate name and hostname should match.Īlso, our Support Engineers see problems with the certain versions of apps like CiviCRM, where PEAR SMTP package does not support TLS. When the SMTP server has a self-signed certificate, it can show up the “SMTP: STARTTLS failed” error.įor example, servers having PHP 5.6 will verify peer certificates and host names by default when using SSL/TLS. Let’s discuss the top causes for the STARTTLS failed error.įrom our experience in managing servers, our Support Engineers often see STARTTLS problems due to the server SSL certificate. But, many times STARTTLS failure can block mails. Usually, the servers that offer message submission over port 587 require mail clients to use STARTTLS feature.
STARTTLS is a way to take an existing insecure connection and upgrade it to a secure connection using SSL/TLS. Mail communication can be set up as secure or insecure. Today, we’ll see the top reasons for the “ SMTP: STARTTLS failed” error and how our Support Engineers fix them. Often, bad configuration in custom mail forms or mail module in applications like OsTicket, CiviCRM can show the error “ SMTP: STARTTLS failed“.Īt Bobcares, we help customers to fix these mail errors as part of our Server Support for web hosts. It can end up in the loss order mails, feedback from customers and so on. Problems with website mail module can be really critical.