HOW TO CHECK AND CONFIGURE SMTP AUTHENTICATION FOR ZIMBRA SERVER FROM COMMAND-LINE?

If POP3 and IMAP clients are unable to send mail, check the auth settings and mail mode of the server:

[root@mail ~]# su – zimbra

To check auth setting run below command:

[zimbra@mail ~]# zmprov getServer zimbra.domain.com | grep Auth
zimbraMtaAuthEnabled: TRUE
zimbraMtaAuthHost: zimbra.domain.com
zimbraMtaAuthURL: https://zimbra.domain.com:443/service/soap/
zimbraMtaTlsAuthOnly: TRUE

To check mail mode setting run below command:
[zimbra@mail ~]# zmprov getServer zimbra.domain.com | grep Mode
zimbraMailMode : mixed

In order to use smtp authentication, zimbraMtaAuthEnabled must be set to TRUE. You can set that like this:

[zimbra@mail ~]# zmprov modifyServer zimbra.domain.com zimbraMtaAuthEnabled TRUE

If zimbraMtaTlsAuthOnly is also TRUE, the POP3 and IMAP clients must be configured to use ssl/tls for smtp auth. Similarly, this can be set like this:

[zimbra@mail ~]# zmprov modifyServer zimbra.domain.com zimbraMtaTlsAuthOnly TRUE

In a multi-node installation, make sure that zimbraMtaAuthHost and zimbraMtaAuthURL are set to a mailbox server. If not, the following command will set them appropriately (assuming there is a mailbox node named “mailbox.domain.com”; be sure to use the zmhostname of a mailbox node in your installation).

[zimbra@mail ~]# zmprov modifyServer zimbra.domain.com zimbraMtaAuthHost mailbox.domain.com

Make sure the url in the zimbraMtaAuthURL will work with the zimbraMailMode. For example, if the MailMode is “https” or “mixed”, the AuthURL must begin with “https://” (so that auth will be attempted over ssl), but if the MailMode is “http” (the mail server is only listening on http), the AuthURL must begin with “http://”.

If the URL is wrong, re-set the hostname like this in order to regenerate the AuthURL:

[zimbra@mail ~]# zmprov modifyServer zimbra.domain.com zimbraMtaAuthHost zimbra.domain.com