Better configuration for SMTP Traffic Management function

[samy.janson]

I would like to ask a favor, a recommendation regarding the configuration of the SMTP Traffic Management function.

When I activate it, I understand that the ports to be protected must be added for the system to take effect. But by doing this, several of our clients were unable to send messages when using SMTP from a PHP function or from a web form.

I would like to know which is the most secure and optimal configuration, where any of our clients can send messages in a normal way but protected by this function.

In addition, just in case it is relevant, we use MailChannels as a mail relay to track Outgoing Spam. Mailchannels is configured from exim to transfer the sending of emails through them.

I attach the image of our current configuration.

Thank you !

[skhristich]

Hello Jaime,
Can you open a support ticket https://cloudlinux.zendesk.com/hc/en-us/requests/new so we can take a closer look at your system? You can post the ticket number here and well link this thread to it.
Thank you.

[skhristich]

Hi Sergey !

Thanks, the ticket number is: 90194

[skhristich]

Hi Jaime,
Thank you, our specialists will answer you on the ticket as quickly as possible.

[henri]

What was the answer to this question?

I am also confused by the SMTP Traffic Management functionality.

Are we supposed to enable this or disable this? We only want our customers to use normal SMTP functionality with standard cpanel SMTP ports (and port 26). If we enable this function, will it block all SMTP?

is this the same as whm SMTP Restrictions? Should we enable/disable WHMs SMTP Restrictions feature?

Thanks.

[dbykov]

Hello.

> Are we supposed to enable this or disable this? We only want our customers to use normal SMTP functionality with standard cpanel SMTP ports (and port 26). If we enable this function, will it block all SMTP?

Once the feature is enabled, only whitelisted users and groups will be able to submit an outbound mail using specified ports.
I.e. on cPanel server, for normal mail functionality, it is sufficient to whitelist the mail group. To use mailing lists, - mailman.

> is this the same as whm SMTP Restrictions? Should we enable/disable WHMs SMTP Restrictions feature?

Yes, these features are similar, and I suggest using only either one of them.

[henri]

If we enable this functionality, will the users PHP scripts be blocked from sending email? Or is it only block the "nobody" user from sending email?

[skhristich]

Hello,
In this case, the situation depends on how the sending via Mail() or via SMTP authorization will be performed, and on behalf of which user the sending will be sent.
Emails will be sent if scripts send emails from a user/group who are allowed to send. And such emails will not be sent if emails are sent from a user/group that is not allowed to send.
Please let us know if you have any questions. Thanks in advance!