Sharing is a Wonderful Thing

We, sometimes, need to block users to send emails both the internal and external destinations. For example, you are running an email account for receiving CVs only. However, you don’t have to reply them from this account. All the feedback email is maintained from another account. In that case, you may block the user to send emails. It will not impact in email receiving status. Please follow below guideline to achieve our goal. Goal: Restricting users to send emails to all internal and external domains.   Resolution: Step 1: Open the file smtpd_sender_restrictions.cf and add the below line at the top. root@mail:~# vim /opt/zimbra/conf/zmconfigd/smtpd_sender_restrictions.cf %%contains VAR:zimbraMtaSmtpdSenderRestrictions check_sender_access lmdb:/opt/zimbra/common/conf/restricted_senders%%   Step 2: Execute the below line as Zimbra user. zimbra@mail:~$ zmprov ms `zmhostname` +zimbraMtaSmtpdSenderRestrictions "check_sender_access lmdb:/opt/zimbra/common/con...

We have to regularly monitor server resources e.g. CPU, RAM, Storage, Network Bandwidth Utilization as a day-to-day activity. By monitoring the resources, we may find out the exact cause of any incident that might occur due to full resource utilization. It can guide us to increase the resources as well if require. We are currently using Observium and Cacti to monitor resource utilization. In order to connect the servers with the observium/Cacti, we have to configure SNMPD in the server. You may follow below guideline to install it in CentOS servers. Test Environment: CentOS 7   Step 1: Install SNMPD. [root@vps ~]# yum install net-snmp net-snmp-utils -y   Step 2: Verify that it is set to start at startup [root@vps ~]# systemctl enable snmpd   Step 3: Rename the existing snmpd.conf file and create a new one. [root@vps ~]#mv /etc/snmp/snmpd.conf   /etc/snmp/snmpd.conf.ori [root@vps ~]#touch /etc/snmp/snmpd.conf   Step 4: Configure ...

We have to regularly monitor server resources e.g. CPU, RAM, Storage, Network Bandwidth Utilization as a day-to-day activity. By monitoring the resources, we may find out the exact cause of any incident that might occur due to full resource utilization. It can guide us to increase the resources as well if require. We are currently using Observium and Cacti to monitor resource utilization. In order to connect the servers with the observium/Cacti, we have to configure SNMPD in the server. You may follow below guideline to install it in Ubuntu servers. Test Environment: Ubuntu 16.04 LTS and Ubuntu 18.04 LTS   Step 1: Install SNMPD. root@mail:~# apt-get install snmpd   Step 2: Rename the existing snmpd.conf file and create a new one. root@mail:~#mv /etc/snmp/snmpd.conf   /etc/snmp/snmpd.conf.ori root@mail:~# touch /etc/snmp/snmpd.conf   Step 3: Configure the SNMP community string. root@mail:~# vim /etc/snmp/snmpd.conf rocommunity mystring@3...