Question Spam Protection Web Host?

[safemoon]

Server operating system version

Ubuntu 20.04.6 LTS

Plesk version and microupdate number

Plesk Obsidian Version 18.0.53

Hi,

Recently the dedicated server i use with Plesk Web Host edition got suspended by the hosting provider for email spamming reasons.

I checked the Mail Queue and there were 400+ emails in the queue all from the same domain (custom PHP web app)
I suspect that the suspension was caused by this domain.

What can I do to completely disable email sending through my server's IP? The "Enable mail management functions in Plesk" option was already disabled/unchecked.

All subscriptions/installations on the server run my own PHP app, in my own PHP app there is a way to setup SMTP to send emails.
Is there any setting at server level that could stop any outgoing emails that are not SMTP so my server can potentially avoid getting blacklisted?

Or any other tips to improve the mail integrity?

 

[MarkM]

Sounds like you're looking to disable php's mail function essentially. Check this out;

How to disable PHP mail() function for a spamming domain on Plesk for Linux server? - Support Cases from Plesk Knowledge Base

How to disable PHP mail() function for a spamming domain on Plesk for Linux server? - Support Cases - Plesk Knowledge Base

www.plesk.com

 

[ronanmarco]

To disable non-SMTP email sending through your Plesk server and improve mail integrity; I would suggest to check following things;

1. Ensure PHP apps use SMTP for sending emails.
2. Disable "Enable mail management functions in Plesk."
3. Set firewall rules to control outgoing traffic.
4. Implement email authentication (SPF, DKIM, DMARC).
5. Regularly monitor mail queue and server logs.
6. Check for blacklist status and remove if listed.
7. Use email filtering and anti-spam solutions.