Title: Authentication error Last modified: September 21, 2021 --- # Authentication error * Resolved [useStrict](https://wordpress.org/support/users/usestrict/) * (@usestrict) * [4 years, 8 months ago](https://wordpress.org/support/topic/authentication-error-19/) * Hi, * I’m trying to set up WP Mail SMTP with a new SMTP server and keep getting authentication failure. I contacted the sysadmin and he said the following: * > It is trying to use CRAM authentication, which won’t work. You need to use > either PLAIN or LOGIN. * Is there a way to set the type of authentication? Here is the full error log: * ``` Versions: WordPress: 5.8.1 WordPress MS: No PHP: 7.4.23 WP Mail SMTP: 3.0.3 Params: Mailer: smtp Constants: No ErrorInfo: SMTP Error: Could not authenticate. Host: ***ipp.com Port: 587 SMTPSecure: tls SMTPAutoTLS: bool(true) SMTPAuth: bool(true) Server: OpenSSL: OpenSSL 1.1.0l 10 Sep 2019 Debug: Email Source: WP Mail SMTP Mailer: Other SMTP SMTP Error: Could not authenticate. SMTP Debug: 2021-09-21 15:45:45 Connection: opening to ***ipp.com:587, timeout=300, options=array() 2021-09-21 15:45:46 Connection: opened 2021-09-21 15:45:46 SERVER -> CLIENT: 220 allegro.isipp.com ESMTP Sendmail 8.15.2/8.15.2/Debian-8+deb9u1; Tue, 21 Sep 2021 15:45:46 GMT; (No UCE/UBE) logging access from: [x.x.x.x](FORGED)-x.x.x.x.vultr.com [x.x.x.x.x] (may be forged) 2021-09-21 15:45:46 CLIENT -> SERVER: EHLO ***.com 2021-09-21 15:45:46 SERVER -> CLIENT: 250-***ipp.com Hello 216.128.149.225.vultr.com [216.128.149.225] (may be forged), pleased to meet you250-ENHANCEDSTATUSCODES250-PIPELINING250-EXPN250-VERB250-8BITMIME250-SIZE250-DSN250-AUTH DIGEST-MD5 CRAM-MD5250-STARTTLS250-DELIVERBY250 HELP 2021-09-21 15:45:46 CLIENT -> SERVER: STARTTLS 2021-09-21 15:45:46 SERVER -> CLIENT: 220 2.0.0 Ready to start TLS 2021-09-21 15:45:46 CLIENT -> SERVER: EHLO ***.com 2021-09-21 15:45:46 SERVER -> CLIENT: 250-***ipp.com Hello x.x.x.x.vultr.com [216.128.149.225] (may be forged), pleased to meet you250-ENHANCEDSTATUSCODES250-PIPELINING250-EXPN250-VERB250-8BITMIME250-SIZE250-DSN250-AUTH DIGEST-MD5 CRAM-MD5 LOGIN PLAIN250-DELIVERBY250 HELP 2021-09-21 15:45:46 CLIENT -> SERVER: AUTH CRAM-MD5 2021-09-21 15:45:46 SERVER -> CLIENT: 334 PDE1NTg5NDg4NDcuNDg0OTI5MUBhbGxlZ3JvLmlzaXBwLmNvbT4= 2021-09-21 15:45:46 CLIENT -> SERVER: [credentials hidden] 2021-09-21 15:45:46 SERVER -> CLIENT: 535 5.7.0 authentication failed 2021-09-21 15:45:46 SMTP ERROR: Username command failed: 535 5.7.0 authentication failed SMTP Error: Could not authenticate. 2021-09-21 15:45:46 CLIENT -> SERVER: QUIT 2021-09-21 15:45:46 SERVER -> CLIENT: 221 2.0.0 ***ipp.com closing connection 2021-09-21 15:45:46 Connection: closed SMTP Error: Could not authenticate. ``` * Cheers, Vinny Viewing 4 replies - 1 through 4 (of 4 total) * Thread Starter [useStrict](https://wordpress.org/support/users/usestrict/) * (@usestrict) * [4 years, 8 months ago](https://wordpress.org/support/topic/authentication-error-19/#post-14898109) * I found a solution: * ``` add_filter( 'wp_mail_smtp_custom_options', function( $phpmailer ) { $phpmailer->AuthType = 'LOGIN'; return $phpmailer; } ); ``` * It’d be nice if there were a simpler way to test that, or if the plugin could cycle through the options when something fails. * [tico87](https://wordpress.org/support/users/tico87/) * (@tico87) * [4 years, 8 months ago](https://wordpress.org/support/topic/authentication-error-19/#post-14910994) * > ``` > I found a solution: > > add_filter( 'wp_mail_smtp_custom_options', function( $phpmailer ) { > $phpmailer->AuthType = 'LOGIN'; > > return $phpmailer; > } ); > ``` > * Where to put this line? - This reply was modified 4 years, 8 months ago by [tico87](https://wordpress.org/support/users/tico87/). * [tico87](https://wordpress.org/support/users/tico87/) * (@tico87) * [4 years, 8 months ago](https://wordpress.org/support/topic/authentication-error-19/#post-14910995) * [@usestrict](https://wordpress.org/support/users/usestrict/) Where to put this line? * [Sanjeev Aryal](https://wordpress.org/support/users/sanzeeb3/) * (@sanzeeb3) * [4 years, 8 months ago](https://wordpress.org/support/topic/authentication-error-19/#post-14919576) * Hi [@tico87](https://wordpress.org/support/users/tico87/), * You can check out the documentation on ways to [add custom code snippets](https://www.wpbeginner.com/plugins/how-to-easily-add-custom-code-in-wordpress-without-breaking-your-site/) in your site. * However, it is probably not the same error you’re getting. If that does not fix the issue, please [create a new support post](https://wordpress.org/support/plugin/wp-mail-smtp/#new-topic-0) with the SMTP error. * [@usestrict](https://wordpress.org/support/users/usestrict/) – WordPress (PHPMailer) uses these auth types in order: * CRAM-MD5, LOGIN, PLAIN, XOAUTH2 * But if the receiving SMTP server is not configured correctly, it will fail at the first one. * I hope this clarifies! Viewing 4 replies - 1 through 4 (of 4 total) The topic ‘Authentication error’ 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/) * 4 replies * 3 participants * Last reply from: [Sanjeev Aryal](https://wordpress.org/support/users/sanzeeb3/) * Last activity: [4 years, 8 months ago](https://wordpress.org/support/topic/authentication-error-19/#post-14919576) * Status: resolved