POP3 options

General


Maximum concurrent connections
The thread setting limit for incoming POP connections at one time.

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) (Enterprise Edition only)
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) (Enterprise Edition only)
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 (Professional and Enterprise Editions only)
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'. Click here for more information on NTLM authentication

Enable CRAM-MD5 authentication (Professional and Enterprise Editions only)
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.

Advanced


Use alternate welcome message
This is the welcome message which is displayed to email clients connecting to the service.

Inactivity timeout
Set the inactivity timeout for the POP service. If a connection is inactive for longer than the timeout period (in seconds) then the connection will be closed.

Allow concurrent mailbox access
By default POP servers only allow one connection a mailbox this will change this for MailEnable.

Logging


Enable Logging
Enables W3C logging for the POP service. W3C Logging can specify which fields are logged and the rollover frequency. The directory can also be specified.

Logging Options
Produces a debug and activity log for the POP3 service. Use this to obtain more details about the service.