[FIX] Zimbra Email Not Received

The Zimbra email not received problem occurs when there is an issue is with your firewall or DNS. You can send and receive an email through the Zimbra MTA. For incoming email messages, the Zimbra MTA has to accept the remote mail server's connection requests. Then, it receives email messages for the local users. 

Zimbra Email Not Received

Configure DNS 

  • To send and receives emails, you have to configure the Zimbra MTA in DNS with an A record and an MX record. When the Zimbra MTA receives a mail, it routes the mail through incoming, active, deferred, and hold queues. For receiving emails, the MX record should be configured correctly. One of the main reasons for the Zimbra email not received problem is the MX record configuration.
  • During the installation process, ZCS checks whether the MX record is configured correctly or not. If the MX record is not configured, you will see an error message.
  • In such a case, configure a relay host if you have not enabled DNS yet. After the ZCS installation, navigate to the Global Settings tab followed by the MTA tab.
  • Deselect the Enable DNS lookups checkbox. Type the relay MTA address. Even after configuring the relay host, you have to configure the MX record to receive emails. 
  • Make sure that you have done the configuration correctly and proceed with the following steps to resolve the Zimbra email not received problem.

Steps to sort out the problem

  • When you receive an email message, you have to find where the email is failing. 
  • Try sending an email and check the /var/log/zimbra.log file on your MTA server.
  • If needed, you have to check the other log files.
  • You are recommended to tail the log file as given below while you send the email.
  • tail -f /var/log/zimbra.log
  • Wait until the response. If the response is nothing logged, no connection, or nothing, this means that the issue is related to DNS or your firewall.

Resolve the firewall issue

  • The email server on the internet has to be connected to your MTA server on port 25
  • Sometimes, the issue might be due to a spam filter. In that case, the firewall directs the communication that comes to your email server. 
  • Antivirus software plays a vital role in determining which domains have to be active. So, include your domain in it.
  • If the Zimbra email not received problem is due to a firewall, the issue will be resolved.
  • If not, carry out the remaining steps on this web page.

Resolve the DNS issue

  • As previously mentioned, you must have an MX record. Check once if you have configured your domain in an MX record.
  • For this, use the host -t mx domain command.
  • Wait for a response. It should be either public IP or private IP.
  • If it is the public IP address, ensure that your firewall is forwarding port 25 to the MTA server.
  • In case an email is delivered to the MTA, but you cannot get it to your mailbox, you will see the following line in the /var/log/zimbra/log file.
  • postfix/lmtp … deferred … connection refused
  • It means that there is no port connection to perform the Local Mail Transfer Protocol delivery.
  • You can resolve this issue by using native IP address lookups.
  • If the Zimbra email not received problem persists, get assistance from our technical experts.
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