How to disable Zimbra's duplicate email detection

Zimbra has a duplicate message detection feature to prevent receiving multiple email messages with the same content. Duplicate message checking is enabled by default. To disable it, you can configure the Server level (for everyone) or the Account level as follows.

Disabling Duplicate message check for the whole system

To disable duplicate message checking for every user in Zimbra mail:

[root@ezymailhosting ~]# su - zimbra
[zimbra@ezymailhosting ~]$ zmprov mcf zimbraMessageIdDedupeCacheSize 0
[zimbra@ezymailhosting ~]$ zmmailboxdctl restart

To check:

[root@ezymailhosting ~]# su - zimbra
[zimbra@ezymailhosting ~]$ zmprov gcf zimbraMessageIdDedupeCacheSize

A returned value greater than 0 means duplicate message checking is enabled.

Reading note: The Thai comments in the following block mean “Enable duplicate message checking” for 3000 and “Disable duplicate message checking” for 0.

zimbraMessageIdDedupeCacheSize: 3000   //เปิดใช้งานตรวจสอบ duplicate message
zimbraMessageIdDedupeCacheSize: 0   //ปิดการตรวจสอบ duplicate message

Disabling Duplicate message check for an individual account

1. Go to Preferences.
2. Select Mail.
3. At the bottom of Receiving Messages, there is an option to enable or disable Duplicate message checking.