SMTP Sending Fails with both Amazon SES and Gmail

I’ve just set up PHP list, and I can send messages via the host’s MTA. So, I think it’s configured correctly.

But, my SMTP attempts have failed. I tested it with my Amazon SES credentials and got this error message:

SMTP ERROR: Password command failed: 535 Authentication Credentials Invalid

To see if it was an Amazon-specific issue, I tested it with my Gmail credentials and got a similar message:

SMTP ERROR: Password command failed: 535-5.7.8 Username and Password not accepted.

Here’s the configuration I’ve used:

define('PHPMAILERHOST', '');
$phpmailer_smtpuser = 'xuserx';
$phpmailer_smtppassword = 'xpassx';

I know my username and passwords are correct, so is there a reason I’d get credential errors for both Amazon SES and Gmail SMTP configurations?


You need different credentials to send through SMTP, see

Thanks for this suggestion.

Oddly, I had the correct credentials–as I’ve been using them for SMTP sending for years–but they wouldn’t work with PHPlist.

That said I was able to resolve the issue by simply creating a new set of credentials.

(I also had to change my default email on PHPlist’s configuration page to match the domain listed in my Amazon SES setup. And, this may have been the issue with the Gmail issue in my original post.)

And, if anyone else runs into a similar issues on the Amazon front, this page is also helpful for context:

Thanks again!