To set the Internet connection type go to Configuration → Internet Connection.
9.1 Internet Connection
Kerio MailServer can either be installed on a computer that has a permanent connection to the Internet (leased line, wireless connection, cable modem, xDSL, etc.) or on a com-puter with a dial-up connection (analog or ISDN modem). Using the built-in scheduler you can set when the mailserver will automatically dial out a connection and perform a mail exchange.
Figure 9.1 Internet Connection tab
Chapter 9 Internet Connection
Online
Kerio MailServer is permanently connected to the Internet. Outgoing mail is sent immediately.
Offline
The server is not permanently connected to the Internet. Outgoing mail is stored in a queue and is sent in time intervals set in the Scheduler.
Warning: Offline connection is available only in MS Windows. This option is not supported in Linux and Mac OS systems. That is the reason why the dialog is not available for these operating systems.
Check the Use RAS to connect to Internet option if you intend to dial the line within these time intervals. Dial-up entries created in Windows are offered in the Select RAS line menu. Kerio MailServer can use the username and the password which have been assigned to the appropriate dial-up connection by a user (the Use user and password specified in system option) or you can enter the username and pass-word directly into this dialog (the Specify user and passpass-word option).
Warning: The dial-up connection must be created for all users within the system (this can be defined within definition of an appropriate connection).
Notes:
1. The Offline option can also be used when Use RAS to Connect to Internet is not checked. Kerio MailServer can run on a computer within a local network connected to the Internet by a dial-up line. In the Online mode frequent and uncontrollable requests for dial-out will be made. In the Offline mode Kerio MailServer will re-quest a dial-out only in the time intervals set in the scheduler, which helps optimize connection costs.
2. Kerio MailServer uses the system telephone connection phone list (rasphone.pbk).
No other phone list can be used.
3. The Online option does not switch off the scheduler. Although outgoing mail is sent immediately, the mailserver can retrieve messages from remote POP3 accounts in regular intervals. For details, see chapter16.4.
4. Details about setting the scheduler can be found in chapter10.
9.2 Sending High Priority Messages
9.2 Sending High Priority Messages
If the server is not permanently connected to the Internet (it operates in the offline mode), you can set server to send messages immediately.
Figure 9.2 Sending High Priority Messages tab
Send messages in outgoing queue...
Use this option to send outgoing messages immediately. You can also define if all messages (messages with any priority) or only messages with high priority will be sent.
Allow to establish Dial-up connection...
Use this option to allow to establish dial-up connection automatically if the server receives an outgoing message that is to be sent.
Chapter 10
Scheduling
Kerio MailServer contains a built-in scheduler that can perform three types of actions:
Retrieve mail from remote POP3 mailboxes
— always if at least one POP3 account is defined Send the ETRN command to defined servers
Use this option if at least one ETRN server is defined.
Send mail from the mail queue
— Use this option if the Kerio MailServer host is not permanently connected to the Internet . In all above cases, Kerio Mail Server can dial out a connection (if the settings indicate that the computer where Kerio MailServer is installed is not permanently connected to the Internet — see chapter9).
10.1 Setting Up the Scheduler
The scheduler is set in the Configuration → Scheduling section.
Figure 10.1 Scheduling
Use the Add, Edit and Remove buttons to add, edit or remove an item in the list of scheduled tasks. When adding a new item or editing an existing one a dialog window with the following parameters will be displayed:
Time condition — when the task is to be performed:
Every or At
Once in an interval (Every) or at a certain time (At). For example Every 10 Minutes or At 12:00 every day.
10.1 Setting Up the Scheduler
Figure 10.2 Scheduled Action
Valid only at time
Scheduled action is valid only in a selected time interval. All defined time intervals are displayed in the window; you can edit an interval (by clicking on Edit) or create a new one. See chapter13.2for details.
Action — what task is to be performed:
Send mail in outgoing queue
Send all mail in the queue (if you selected Online in the Configuration → Internet Connection section all mail is sent immediately and this option has no effect).
Download messages from POP3 mailboxes
Retrieve mail from remote POP3 mailboxes (only valid if at least one remote mailbox is defined in the Configuration → POP3 Download section). The same scheduling applies to all POP3 mailboxes.
Invoke mail transfer by sending ETRN...
Receive email using the ETRN command (only valid if there is at least one SMTP server defined in the Configuration → ETRN Download section). The same schedul-ing applies to all SMTP servers.
Chapter 10 Scheduling
Optional parameters:
Allow to establish Dial-up connection...
Dials out a connection if the line is currently down. If this option is not ticked, the task will only be performed when the line is dialed out.
10.2 Optimal Scheduling
Optimal scheduling settings depend on the way the incoming mail is received and on the Internet connection type available to Kerio MailServer.
• If the computer with Kerio MailServer is permanently connected to the Internet (On-line) and all incoming email is received using the SMTP protocol (MX records for all local domains point to the computer where Kerio MailServer is installed and there is no remote POP3 account or ETRN server) there is no need to set up any scheduling.
• If a permanent connection to the Internet is available and at least one POP3 account is defined or mail reception is conducted using the ETRN command, scheduling must be set.
In this case intervals between individual actions can be quite short (e.g. 5 minutes) as the number of connections does not influence the cost and there is no need to consider the time needed for dialing.
• If Kerio MailServer is connected to the Internet via a dial-up line, it is not perma-nently accessible from the Internet and mail reception is conducted using the ETRN command or from remote POP3 mailboxes. In this case it is necessary to set up scheduling to enable Kerio MailServer to dial out, send mail from the queue and re-ceive email when needed.
In all of the above examples where scheduling is recommended, all options in the Action field can be selected (Send mail in outgoing queue and Invoke mail transfer by sending ETRN command to configured SMTP servers). If the mail queue is empty or no POP3 account is defined, Kerio MailServer will automatically move on to the next task.