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 (Online) 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 permanently 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 receive 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.