Step 1:
Open file /opt/zimbra/conf/zmconfigd/smtpd_sender_restrictions.cf and add the below line at the top.
check_sender_access lmdb:/opt/zimbra/postfix/conf/restricted_senders
Step 2:
Open file /opt/zimbra/conf/zmconfigd.cf and add below lines before “RESTART mta”.
POSTCONF smtpd_restriction_classes local_only POSTCONF local_only FILE postfix_check_recipient_access.cf
Note: We can find like below
SECTION mta DEPENDS amavis ----------- ----------- ----------- RESTART mta
Step 3:
Create a file /opt/zimbra/conf/postfix_check_recipient_access.cf and add the following line.
check_recipient_access lmdb:/opt/zimbra/common/conf/local_domains, reject
Step 4:
Create a file /opt/zimbra/common/conf/restricted_senders and enter the list of users that you want to block. Follow this syntax:
user@yourdomain.com local_only
Step 5:
[zimbra@mail ~]# vi /opt/zimbra/common/conf/local_domains sajjan.com.np OK
i.e.: Allow User/Domain (user@domain.com OK/domain.com OK)
Step 6:
Set ownership permissions for created files
chown zimbra:zimbra /opt/zimbra/conf/postfix_check_recipient_access.cf chmod 644 /opt/zimbra/conf/postfix_check_recipient_access.cf
chown :zimbra /opt/zimbra/common/conf/restricted_senders chmod 775 /opt/zimbra/common/conf/restricted_senders
chown :zimbra /opt/zimbra/common/conf/local_domains chmod 775 /opt/zimbra/common/conf/local_domains
Step 7:
Run the below commands as Zimbra user.
postmap /opt/zimbra/common/conf/restricted_senders postmap /opt/zimbra/common/conf/local_domains zmmtactl stop zmmtactl start
