MailEnable Professional Guide
POP - General

The following table outlines the configuration options for MailEnable’s POP service:



Maximum concurrent connections

The number of concurrent connections from email clients that the service will allow.

Alternate @ characters

Some older mail clients don't allow the use of @ in the username section. Since the MailEnable usernames are formatted in mailboxname@postoffice format, this may cause problems. To solve this, MailEnable can specify the characters that can be used as a substitute. Just enter the list of characters such as #$%. This will allow users to log on using mailboxname@postoffice, mailboxname#postoffice, mailboxname$postoffice and mailboxname%postoffice.

POP Port

The port MailEnable will allow client POP connections on. The default is 110.

POP Enable SSL (Default Port)

Enables SSL encryption for the default port that POP is running on.  When enabling SSL make sure a valid SSL certificate has been selected in the MailEnable Administration > Server > Localhost Properties > SSL tab

Also listen on alternate port

Allows the POP service to listen on an alternate port. Usually this is done to cater for clients who may be on connections where their outbound port 110 has been blocked.

POP Enable SSL (Alternate Port)

Enables SSL certificate encryption for the alternate port that POP is running on. The default port number is 995.  When enabling SSL make sure that a valid SSL certificate has been selected in the MailEnable Administration  > Server > Localhost Properties > SSL tab.

Enable APOP authentication

Usually, the users’ username and password are sent in clear text format (i.e. not encrypted). Enabling this option will force clients to enable APOP authentication on their mail client software. Make sure users are using software that supports APOP, otherwise they will not be able to receive email. Some older mail clients do not support APOP.

Enable NTLM authentication

If this feature is 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 to 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 section.

Enable CRAM-MD5 authentication

CRAM-MD5 Challenge-Response Authentication Mechanism is intended to provide an authentication extension 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.  

Timeout for idle connections

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

Access Control

The Access Control feature can specify who can connect to the POP service. A list of IP addresses that are either banned from connecting, or are the only ones allowed to connect by selecting the Access Control button can be specified.

IP Addresses to bind POP to

It is possible to select the IP addresses that the POP service will be bound to. On a multi-homed machine you may only wish to 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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