Plesk 12 sendmail issues

[Ivo]

First of this is my server configuration:

OS CloudLinux Server 6.7 (Aleksei Gubarev) Plesk version 12.0.18 Update #65,

And now this is my problem.

I have disabled sendmail via panel, and set outoging mail limit 50 e-mail per inbox. Everything was working fine till recently when we started to have issues with mails.

Despite sendmail being disabled this works pretty good in command line

echo -e "To:[email protected] \nSubject: Test mail from web\n\n Test mail from web via senmail\n" | sendmail -t -F [email protected]

Php works fine to, via php script despite php mail function being disabled in php ini (/opt/alt/php54/etc/php.ini)

mail("[email protected]","hello","test mail function");

And the worst thing is both of those methods ignore outgoing mail limit that is set in panel.

So basicly someone can hack one of our website and starts sending spam (which happened already).

My questions are simple. How to disable sendmail permanently and how to disable php mail function on whole server.

Ty in advance.

 

[cepesh84]

@Ivo,

Plesk allows you to enable/disable sendmail for a certain system user.
I've checked your steps for certain OS and Plesk version and couldn't reproduce the problem.
I've created a subscription jsmith.com with [email protected] email address. Next i've changed (disable sendmail) Outgoing Mail control settings for this subscription (system user). So i log in by SSH as this user and tried to send a some mail:

• mail -s "Test Subject" [email protected] < /dev/null

And i've got the following:

• Mail handler 'limit-out' said: REPLY:554:5.7.0 The message could not be sent. You are not allowed to use sendmail utility.

Then i've enable sendmail for this system user and sent a few emails successfully before subscription's limit for outgoing mail. Then i've got the following error message:

• Mail handler 'limit-out' said: REPLY:554:5.7.0 Your message could not be sent. The limit on the number of allowed outgoing messages was exceeded. Try again later.

What IMAP/POP3 and SMTP servers do you use?
You can find out it by using the following CLI uitility call:

• plesk sbin mailmng-server --features

 

[burnley]

Ivo,

If you're using Postfix try and have a look at authorized_submit_users parameter. You can simply forbid everyone else but root to send emails via the local sendmail wrapper using:
authorized_submit_users = root
YMMV
See http://www.postfix.org/postconf.5.html

 

[Ivo]

@cepesh84

You are right, mail -s "Test Subject" [email protected] < /dev/null does not work however i never said that this works, i said that this command works and it still does...
echo -e "To:[email protected] \nSubject: Test mail from web\n\n Test mail from web via senmail\n" | sendmail -t -F [email protected]
If im not mistaken that uses sendmail function also or?


@burnley

Your method worked, ty. Any idea how to block php mail function globaly to? Tried via php.ini but it seems it didn't work.

 

[Ivo]

Actually
authorized_submit_users = root is not a good solution, problem is now everyone who is using sendmail is getting blocked nnot only on our server, so if someone outside is using sendmail our server wont accept that.