MailEnable Enterprise Guide
IMAP - General

The setup of IMAP is relatively simple, as it is a service that is bound to a listening port similar to HTTP.  The IMAP service listens on this port and receives mail and various commands from the server.  It is important to enable the default port of 143 on the firewall or any other port number stipulated in the General properties of the IMAP service. To help in server traffic and load, also stipulate which IP address to bind the service to. 

Within the Administration Console navigate to the following location: Servers > Localhost > Services and Connectors branch, right click on the IMAP icon and select Properties from the popup menu. The General tab options are explained below:



Max Concurrent connections (threads)

The number of threads that will be used by the IMAP service to handle client requests.

IMAP port

Port for listening on. Default is 143.

IMAP Enable SSL (Default Port)

This will enable SSL certificate encryption for the default port that IMAP is running on.  Place a tick in this box to enable the service. This also has to be enabled at a server level in the MailEnable Administration program under  Server >Localhost Properties > SSL tab.

Also listen on alternate port

An alternate port can be selected.

IMAP Enable SSL (Alternate Port)

This will enable SSL certificate encryption for the alternate port that IMAP is running on.  The default port number is 993.  Place a tick in this box to enable. The service also has to be enabled at a server level in the MailEnable Administration program > Server > Localhost Properties > SSL tab.

Client Connections

Select either an unlimited number of client connections, or specify a maximum number of concurrent connections that the service will allow. Specifying a maximum number of connections may reduce server load by limiting the threads that IMAP can use. Be aware that IMAP clients can open multiple connections to the server for the same mailbox.

Timeout for idle connections

If this setting is enabled and a client connection has not passed any commands to the server for the set period of time, the connection will be dropped by the server. 

Enable public folders

Public Folders allow one or more mailboxes under the post office to share data (messages in a folder that is seen by all mailboxes in the post office.)

Anything placed in this folder (Program Files\MailEnable\Post Offices\[Post Office Name]\Pubroot) will become visible to all other mailboxes in the post office.  This feature must be enabled for the post office in Post Office Properties.

Enable NTLMv1 authentication

If enabled then secure authentication between the server and the supported client is enabled.  This will allow the server to accept requests from the client to use secure transmissions for the authentication method.  The client also has to be enabled use this secure authentication. For example, in Outlook the feature is called SPA – Secure Password Authentication.  More information on NTLM can be found in the Overview of NTLM authentication. NTLMv2 is not supported.

Enable CRAM-MD5 authentication

CRAM-MD5 Challenge-Response Authentication Mechanism is intended to provide an authentication extension to IMAP4 that neither transfers passwords in clear text nor requires significant security infrastructure in order to function. Only a hash value of the shared password is ever sent over the network, thus precluding plaintext transmission.  

Enable XLIST support This option allows the IMAP service to tell the email client what folders are the Junk, Deleted Items, etc. Since clients vary the name of these, this helps the client match it what the server has configured.

IP Addresses to bind to

It is possible to select the IP addresses that the POP service will be bound to. On a multi-homed machine it may be desirable to only allow connections on particular IP addresses. ‘Always bind all IPs’ will allow connections on all IP addresses that are configured for the machine.




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