Shulou(Shulou.com)05/31 Report--

Today, I will talk to you about how extmail restricts some users to send email to aliases. Many people may not know much about it. In order to make you understand better, the editor summarized the following content for you. I hope you can get something according to this article.

The post office system used by the company is set up by extmail. Recently, there is a demand that only a limited number of users are allowed to send mail to alias users. Alias mailboxes are group mailboxes, which contain the email addresses of all the people in the company. As long as you send mail to this alias mailbox, everyone will receive the mail. Alias mailbox gives me convenience at the same time, that is, there is a certain risk, that is, as long as spammers send mail to this mailbox, the result is unimaginable, so there is the above demand, nonsense, the configuration method:

I. Environment

# lsb_release-a

LSB Version:: core-4.0-amd64:core-4.0-ia32:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-ia32:printing-4.0-noarch

Distributor ID: CentOS

Description: CentOS release 5.9 (Final)

Release: 5.9

Codename: Final

# getconf LONG_BIT

sixty-four

# rpm-qa | grep postfix

Postfix-2.6.2-5hzq

II. Configuration

2.1 modify / etc/postfix/main.cf file

Add the following two lines:

Smtpd_restriction_classes = xtone

Xtone = check_sender_access hash:/etc/postfix/allow2all, reject

And in the smtpd_sender_restrictions section, it is modified as follows

Smtpd_sender_restrictions =

Check_recipient_access hash:/etc/postfix/xtome.com, (this behavior is new)

Permit_mynetworks

Reject_sender_login_mismatch

Reject_authenticated_sender_login_mismatch

Reject_unauthenticated_sender_login_mismatch

2.2 create two profiles

# cd / etc/postfix

# cat allow2all

Test@xtone.com ok

# cat xtone.com

Xt.group@xtone.com xtone

2.3 create hash files for the two files you just created

# postmap hash:/etc/postfix/allow2all

# postmap hash:/etc/postfix/xtone.com

Restart the service

# service postfix restart

IV. Verification

The above configuration only allows the user test@xtone.com to send mail to the alias mailbox xt.group@xtone.com; in this case, just use the allowed mailbox (test@xtone.com) and other unauthorized mailboxes to send an email to the alias mailbox for testing.

After reading the above, do you have any further understanding of how extmail restricts certain users from sending emails to aliases? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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