Spam being sent even with sendmail disabled

[Xavier12]

Hi guys,

We specifically disable sendmail to prevent Wordpress users from being vulnerable to contact form manipulation to send spam. Our customer was reported for sending spam with an email address that doesn't exist in Plesk. A bit confused as to how this is being done if sendmail is disabled and they do not have an email address created based on the one that was mentioned.

Please advise, thnx

 

[xxx]

Take a look at mail header of the email your customer receive. There you can verify if the email is really from your server.
If so, take a look at maillog at the time your customer got the email and check which account sends the email.