Title: Authentication Error SOMEtimes? Last modified: August 10, 2022 --- # Authentication Error SOMEtimes? * Resolved [wbenterprises](https://wordpress.org/support/users/wbenterprises/) * (@wbenterprises) * [3 years, 10 months ago](https://wordpress.org/support/topic/authentication-error-sometimes/) * I have an error log which shows four emails being sent at the same time. * Two of them failed due to authentication, but two of them did not. What could be causing this failure rate? Going back in my log, I see that it happens too frequently. It doesn’t seem to matter which plugin is sending the email. Could you assist in understanding what the root cause may be, please? * Again, this doesn’t happen every time, it’s only happening SOMEtimes… * Debug log shows this: * Mailer: Other SMTP SMTP Error: Could not authenticate. Debug Output: Connection: opening to smtp.hostinger.com:587, timeout=300, options=array() Connection: opened SERVER -> CLIENT: 220 ESMTP smtp.hostinger.com CLIENT -> SERVER: EHLO _[mydomain is here]_ SERVER -> CLIENT: 250-smtp.hostinger.com 250-PIPELINING 250-SIZE 48811212 250-ETRN 250-STARTTLS 250-AUTH PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN CLIENT -> SERVER: STARTTLS SERVER -> CLIENT: 220 2.0.0 Ready to start TLS CLIENT -> SERVER: EHLO _[mydomain is here]_ SERVER -> CLIENT: 250-smtp.hostinger. com 250-PIPELINING 250-SIZE 48811212 250-ETRN 250-AUTH PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN CLIENT -> SERVER: AUTH LOGIN SERVER -> CLIENT: 454 4.7.0 Temporary authentication failure: Connection lost to authentication server SMTP ERROR: AUTH command failed: 454 4.7.0 Temporary authentication failure: Connection lost to authentication server SMTP Error: Could not authenticate. CLIENT -> SERVER: QUIT SERVER -> CLIENT: 221 2.0.0 Bye Connection: closed SMTP Error: Could not authenticate. Viewing 3 replies - 1 through 3 (of 3 total) * Plugin Support [Darshana](https://wordpress.org/support/users/darshanaw/) * (@darshanaw) * [3 years, 10 months ago](https://wordpress.org/support/topic/authentication-error-sometimes/#post-15909907) * Hi [@wbenterprises](https://wordpress.org/support/users/wbenterprises/), * Thanks for reaching out! According to your debug log, the SMTP connection lost when authenticating your email account. This means your email server is not responding properly when your website is sending emails. * Please get in touch with your hosting support with the full error log, and they should be able to assist you further. * I hope this helps. Thanks! * Thread Starter [wbenterprises](https://wordpress.org/support/users/wbenterprises/) * (@wbenterprises) * [3 years, 9 months ago](https://wordpress.org/support/topic/authentication-error-sometimes/#post-15933327) * I have been TRYING to work with my provider on this issue, but they are INSISTING it is not their server. They claim it is my credentials or the plug-in. However, my emails are sending about 90% of the time. Here is the error using SSL instead of TLS: * Mailer: Other SMTP SMTP Error: Could not authenticate. Debug Output: Connection: opening to ssl://smtp.hostinger.com:465, timeout=300, options=array() Connection: opened SERVER -> CLIENT: 220 ESMTP smtp.hostinger.com CLIENT -> SERVER: EHLO _[ redacted]_ SERVER -> CLIENT: 250-smtp.hostinger.com 250-PIPELINING 250-SIZE 48811212 250-ETRN 250-AUTH PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250-DSN 250 CHUNKING CLIENT -> SERVER: AUTH LOGIN SERVER -> CLIENT: 454 4.7.0 Temporary authentication failure: Connection lost to authentication server SMTP ERROR: AUTH command failed: 454 4.7.0 Temporary authentication failure: Connection lost to authentication server SMTP Error: Could not authenticate. CLIENT -> SERVER: QUIT SERVER -> CLIENT: 221 2.0.0 Bye Connection: closed SMTP Error: Could not authenticate. * Could you please shed more light on this issue and what the error means? * ``` Recent logs: Event #4929 Debug An email request was sent. Ultimate Member 19-August-2022 at 1:21 pm Event #4928 Debug An email request was sent. Ultimate Member 19-August-2022 at 1:21 pm Event #4927 Debug An email request was sent. Ultimate Member 19-August-2022 at 1:21 pm Event #4926 Debug An email request was sent. WP Core 19-August-2022 at 10:22 am Event #4925 Debug An email request was sent. WP Core 19-August-2022 at 10:17 am Event #4924 Debug An email request was sent. WP Core 19-August-2022 at 10:16 am Event #4923 Debug An email request was sent. WP Core 19-August-2022 at 10:16 am Event #4922 Debug An email request was sent. myCred 19-August-2022 at 10:12 am Event #4921 Debug An email request was sent. myCred 19-August-2022 at 10:04 am Event #4920 Debug An email request was sent. Ultimate Member 19-August-2022 at 9:14 am Event #4919 Debug An email request was sent. Ultimate Member 19-August-2022 at 9:14 am Event #4918 Debug An email request was sent. Ultimate Member 19-August-2022 at 9:14 am Event #4917 Debug An email request was sent. Ultimate Member 19-August-2022 at 5:40 am Event #4916 Debug An email request was sent. Ultimate Member 19-August-2022 at 5:39 am Event #4915 Debug An email request was sent. Ultimate Member 19-August-2022 at 5:39 am Event #4914 Debug Mailer: Other SMTP SMTP Error: Could not authenticate. Debug Output: Connection: opening to ssl:/... myCred 18-August-2022 at 9:43 pm Event #4913 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 18-August-2022 at 9:43 pm Event #4912 Debug An email request was sent. Ultimate Member 18-August-2022 at 9:41 pm Event #4911 Debug An email request was sent. Ultimate Member 18-August-2022 at 9:40 pm Event #4910 Debug An email request was sent. Ultimate Member 18-August-2022 at 9:40 pm Event #4909 Debug Mailer: Other SMTP SMTP Error: Could not authenticate. Debug Output: Connection: opening to ssl:/... myCred 18-August-2022 at 5:16 am Event #4908 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 18-August-2022 at 5:16 am Event #4907 Debug An email request was sent. Ultimate Member 18-August-2022 at 4:59 am Event #4906 Debug An email request was sent. Ultimate Member 18-August-2022 at 4:59 am Event #4905 Debug An email request was sent. Ultimate Member 18-August-2022 at 4:59 am Event #4904 Debug An email request was sent. Ultimate Member 18-August-2022 at 4:32 am Event #4903 Debug An email request was sent. Ultimate Member 18-August-2022 at 4:32 am Event #4902 Debug An email request was sent. Ultimate Member 18-August-2022 at 4:32 am Event #4901 Debug An email request was sent. myCred 17-August-2022 at 1:05 pm Event #4900 Debug An email request was sent. myCred 17-August-2022 at 10:59 am Just the recent (filtered) error logs: Event #4913 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 18-August-2022 at 9:43 pm Event #4908 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 18-August-2022 at 5:16 am Event #4856 Error Mailer: Other SMTP SMTP Error: Could not authenticate. Ultimate Member 13-August-2022 at 11:12 pm Event #4847 Error Mailer: Other SMTP SMTP Error: Could not authenticate. WP Mail SMTP 13-August-2022 at 12:24 pm Event #4841 Error Mailer: Other SMTP SMTP Error: Could not authenticate. Ultimate Member 12-August-2022 at 3:11 pm Event #4835 Error Mailer: Other SMTP SMTP Error: Could not authenticate. Ultimate Member 12-August-2022 at 5:09 am Event #4832 Error Mailer: Other SMTP SMTP Error: Could not authenticate. Ultimate Member 11-August-2022 at 10:13 pm Event #4828 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 11-August-2022 at 7:04 pm Event #4824 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 11-August-2022 at 5:54 pm Event #4798 Error Mailer: Other SMTP SMTP Error: Could not authenticate. myCred 10-August-2022 at 1:04 am ``` - This reply was modified 3 years, 9 months ago by [wbenterprises](https://wordpress.org/support/users/wbenterprises/). - This reply was modified 3 years, 9 months ago by [wbenterprises](https://wordpress.org/support/users/wbenterprises/). * Plugin Support [Darshana](https://wordpress.org/support/users/darshanaw/) * (@darshanaw) * [3 years, 9 months ago](https://wordpress.org/support/topic/authentication-error-sometimes/#post-15972248) * Hi [@wbenterprises](https://wordpress.org/support/users/wbenterprises/), * I apologize for the trouble! As you can see within the error message, `connection lost to authentication server` this is an intermittent connection issue. * In that case, try configuring an alternative mailer on your site. * You can see all the available mailers from [here](https://wpmailsmtp.com/docs/a-complete-guide-to-wp-mail-smtp-mailers/) and configure a mailer of your choice. * I hope this helps! Viewing 3 replies - 1 through 3 (of 3 total) The topic ‘Authentication Error SOMEtimes?’ is closed to new replies. * ![](https://ps.w.org/wp-mail-smtp/assets/icon-256x256.png?rev=1755440) * [WP Mail SMTP by WPForms - The Most Popular SMTP and Email Log Plugin](https://wordpress.org/plugins/wp-mail-smtp/) * [Frequently Asked Questions](https://wordpress.org/plugins/wp-mail-smtp/#faq) * [Support Threads](https://wordpress.org/support/plugin/wp-mail-smtp/) * [Active Topics](https://wordpress.org/support/plugin/wp-mail-smtp/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/wp-mail-smtp/unresolved/) * [Reviews](https://wordpress.org/support/plugin/wp-mail-smtp/reviews/) * 3 replies * 2 participants * Last reply from: [Darshana](https://wordpress.org/support/users/darshanaw/) * Last activity: [3 years, 9 months ago](https://wordpress.org/support/topic/authentication-error-sometimes/#post-15972248) * Status: resolved