Title: authentication failed error
Last modified: August 24, 2016

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# authentication failed error

 *  Resolved [Chuck Moulton](https://wordpress.org/support/users/chuckmoulton/)
 * (@chuckmoulton)
 * [11 years ago](https://wordpress.org/support/topic/authentication-failed-error/)
 * I’m getting a lot of emails with the following error message:
 * > Authentication failed: Bad username / password
 * Half of the emails seem to go through, half don’t. But the username / password
   is the same for all emails sent through my SMTP server (SendGrid), so I don’t
   see why half would authenticate and half wouldn’t.
 * I didn’t have this problem with other SMTP plugins for WordPress.
 * Any ideas what’s going on and how to fix it?
 * [https://wordpress.org/plugins/postman-smtp/](https://wordpress.org/plugins/postman-smtp/)

Viewing 3 replies - 1 through 3 (of 3 total)

 *  Plugin Author [Jason Hendriks](https://wordpress.org/support/users/jasonhendriks/)
 * (@jasonhendriks)
 * [11 years ago](https://wordpress.org/support/topic/authentication-failed-error/#post-6154504)
 * Hi Chuck! Isn’t email a pain??
 * > I didn’t have this problem with other SMTP plugins for WordPress.
 * Frankly, you wouldn’t have known if you had this problem with other plugins. 
   There would have been no record of the error.
 * I have no idea why the SendGrid server would be intermittently rejecting your
   authentication. Definitely sounds like a problem on their end. If you want, [send me the transcript](http://programmer.jasonhendriks.com/contact/)
   of the failed email (from Postman’s log) and I will confirm to you the username
   and password Postman sent. It’s right there in the log.
 * Have you tried the SendGrid plugin? I know it has an API option which means you
   just put in an API key instead of a username and password. That might be more
   reliable! Unfortunately I don’t have any experience with SendGrid’s service myself.
 * [https://wordpress.org/plugins/sendgrid-email-delivery-simplified/](https://wordpress.org/plugins/sendgrid-email-delivery-simplified/)
 * Cheers!
    Jason
 *  Thread Starter [Chuck Moulton](https://wordpress.org/support/users/chuckmoulton/)
 * (@chuckmoulton)
 * [11 years ago](https://wordpress.org/support/topic/authentication-failed-error/#post-6154521)
 * > Frankly, you wouldn’t have known if you had this problem with other plugins.
   > There would have been no record of the error.
 * It’s true that there would be no log to check. However, with the previous plugins
   I always got the subscriber emails myself. In this case I frequently did not 
   get emails sent to myself as a subscriber. I suppose have no way of knowing whether
   other subscribers failed to get emails with the other plugins.
 *  Thread Starter [Chuck Moulton](https://wordpress.org/support/users/chuckmoulton/)
 * (@chuckmoulton)
 * [11 years ago](https://wordpress.org/support/topic/authentication-failed-error/#post-6154526)
 * > Have you tried the SendGrid plugin?
 * No, I was not aware SendGrid had a WordPress plugin. Thank you for pointing that
   out to me! I will try it late tonight (I try not to mess with settings during
   the day so as not to disrupt my site).

Viewing 3 replies - 1 through 3 (of 3 total)

The topic ‘authentication failed error’ is closed to new replies.

 * ![](https://s.w.org/plugins/geopattern-icon/postman-smtp_7c7b78.svg)
 * [Postman SMTP Mailer/Email Log](https://wordpress.org/plugins/postman-smtp/)
 * [Frequently Asked Questions](https://wordpress.org/plugins/postman-smtp/#faq)
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## Tags

 * [authentication](https://wordpress.org/support/topic-tag/authentication/)

 * 3 replies
 * 2 participants
 * Last reply from: [Chuck Moulton](https://wordpress.org/support/users/chuckmoulton/)
 * Last activity: [11 years ago](https://wordpress.org/support/topic/authentication-failed-error/#post-6154526)
 * Status: resolved