What are the proper relay settings for mail?

[tuberb]

I am having a mail relay problem with my server, which may be related to a misconfiguration (or may not be), but I am getting advice from my hosting provider that does not make sense to me.

As I understand it, the proper setting for me for mail relay in Plesk should be "authorization is required", with the authorization type being "SMTP". This should allow users with accounts to send mail through the server, but block unauthorized mail (i.e. spam) from using my server to get delivered.

When my server is set that way, spammers are able to use it to send mail, and the server shows as an open relay when tested. When I reset the server to relay "closed" (which is what my ISP is telling me to do) spammers can't use the mail server, but neither can my authorized users. Mail sent from authorized users just goes through the server (I can see it in the mail queue) but never gets delivered.

As a side note, when we try to restart qmail, we get the following message:

Service is not available now, probably your Plesk is misconfigured.
Contact Your provider for details.

Internal Plesk error occurred: Unable to make action: Unable to manage service by mailmng: mailmng: Service /etc/init.d/qmail failed to start System error 2: No such file or directory

This is after my ISP reinstalled qmail yesterday in response to the same problem with qmail not starting.

So, what are the correct settings for mail relay, and does it look like my symptoms are a result of my Plesk being "misconfigured"? And if so, how can I get it fixed?

Thanks,

Barry

 

[jwdick]

The correct settings ( in my opinion ) are:

Authorization required
SMTP is checked
POP3 lock time is UNCHECKED.


If these settings allow spammers to use your box, then your qmail is misconfigured. Your error message indicates that the qmail service cannot start because the file is not there. Try #service qmail restart

 

[ib1984]

Barry, you may also need to look at IPs whitelist ('Server' -> 'Mail' -> 'Whitelist') -- these IPs are allowed to send mail through server w/o authorization. Also, SMTP authorization does not mean that spammers cannot send mail TO your server -- they just cannot relay the mail THROUGH your server using either mail addresses which belongs to your server or to some other server.
As to checking relay if it requires authorization -- this need to be done from the host which is not listed in server's whitelist, otherwise authorization is not required.