Webform unable to send email – SMTP auth test does send

As the subject says, I have an old site that was functioning properly…not sure when it went south.

SMTP auth settings are as follows: SMTP server is onsite exchange, port 25, no encryption, no auth. No errors and the email is sent as desired.


When attempting to submit, this error is thrown and no email is sent.


I can’t find anything in the webform itself that seems pertinent.

Any ideas? I’m a total Drupal noob, please consider if responding.


Drupal version: 

Source: https://www.drupal.org/taxonomy/term/22/feed