旅程的起點

參考資料：https://wiki.zimbra.com/wiki/Incoming_Mail_Problems

Zimbra Port 7025 作為 LMTP(本地郵件傳輸協議) 使用

將zimbraMtaLmtpHostLookup設為本地搜尋(搭配DNS Split)即可排除

官方原文：
Mail is delivered to the MTA, but not to the mailbox
If there is a line in the /var/log/zimbra.log like:

postfix/lmtp ... deferred ... connection refused
There is no connection to port 7025 to perform Local Mail Transfer Protocol (LMTP) delivery.

This is nearly always caused by a host that is configured on private IP Space (or using NAT) and that does not have an interface for the public IP address the server resides on. This can be easily fixed by simply using native IP address lookups for lmtp rather than DNS. Alternatively, you could have your internal network's domain name configured to lookup differently internally than it does externally. Using that method is beyond the scope of this document.

ZCS 8.5 or above onwards this attribute is now in ldap - zimbraMtaLmtpHostLookup
In case that you are using Single Server, be aware always of the Global Config as well:
Once this is done, you'll need to restart the mta: