Definition of Domains

Domains are defined in the Configuration → Domains section.

In the Internet hostname field, enter the Internet (DNS) name of the computer where Kerio MailServer is installed (typically, this would be the name of the computer with the appended primary domain name — this way the server name is automatically gener-ated by the configuration wizard). Server names are used for server identification while establishing SMTP traffic.

Upon initializing SMTP communication, the EHLO command is used for retrieving reverse DNS record. The server that communicates with Kerio MailServer can perform checks of the reverse DNS record.

8.1 Definition of Domains

Figure 8.1 Domains

Note: If Kerio MailServer is running behind NAT, enter the Internet hostname that can be converted to the IP address of the sending server, i.e. the internet hostname of the firewall.

Click Advanced to set location of public folders:

• Unique for each domain — each domain contains its own public folders. This config-uration does not allow any user for accessing a folder of another domain.

If there are more domains with user mailboxes created in Kerio MailServer, each of these domains must have at least one public folder administrator specified in the User accounts section (see chapter14).

• Global for all domains — users of all domains share the same public folders.

Use the Set as primary button to change domain type (the same may be performed using the context menu). Any domain ordered as the first one is always primary [Local (primary)]. Other domains can be set either as Local (primary) or as Local.

Note: Any new domain you add can be set as Local (primary), even when another domain already has this status. By taking this step, however, the new domain becomes primary and the former primary domain becomes local only.

Create a new domain by clicking on the Add button.

Deleting of domains

You can delete the domain using the Delete button. A domain cannot be deleted if:

• user accounts or groups have been already defined within the domain. All accounts

Chapter 8 Domains

• the aliases are defined in it. First, delete all the aliases (for details, see chapter16.3).

• it is the primary domain. However, you can create another domain and define it as primary. Then, the former domain can be deleted.

8.2 General

Basic domain parameters — the General bookmark:

Figure 8.2 Domain settings — basic parameters

Domain

The name of the new domain

Note: No national or special characters are allowed for the name of the new domain (see Allowed and prohibited characters in the domain name table).

Examples of correct names:

company.com; server.company.com; server-company.com;

server---company.com Examples of incorrect names:

company..com; company...com; .company.com; company.com.;

server_company.com

8.2 General

Character Allowed Character Prohibited

a-z allowed / prohibited

0-9 allowed \ prohibited

A-Z allowed .. prohibited

. allowed when not at the

beginning and/or the end of the string and when there are not two dots next to each other

. prohibited when at the

beginning and/or at the end of the string

- allowed * prohibited

_ prohibited

Table 8.1 Allowed and prohibited characters in the domain name

Description

A notation about the domain created (for the administrator only).

Message size limit

The maximum size limit for all sent messages (via SMTP, WebDAV, etc.). The limit applies only to the domain specified.

It is recommended to activate this option for each domain that contains user mail-boxes. This way, you can prevent the internet connection from being overloaded with messages with large attachments (images, clips, music, etc.).

If the limit is set to 0, Kerio MailServer behaves the same way as if no limit was set.

The message size limit can be also set for individual users separately (see

chap-ter14.2). The limit set for a particular user has higher priority than the limit set for

the domain.

Restoring deleted items

Using this option, the deleted items (messages, events, contacts, tasks) can be moved back to the Deleted items folder. Users can also specify how long the items should be preserved so that they can be restored when needed.

The settings depend on the number of user mailboxes in Kerio MailServer and free disc space. However, the time must not exceed one year, i.e. 365 days. If the specified number is too large, the domain settings cannot be saved.

It is recommended to enable this option for all domains that contain user mail-boxes, so that the items deleted by mistake (messages, events, contacts or tasks) can be easily restored.

To restore the items and move them back to Deleted items folder, select Configu-ration → Domain settings → User accounts. For more information about restoring items for selected users, see chapter14.7.

Chapter 8 Domains

User count limit

This option is useful especially when administration of user accounts via web in-terface is used (see chapter27). Users with administration rights cannot break this limit.

8.3 Aliases

It is possible to define any number of virtual domains (aliases) for the each email domain.

Virtual domains are alternative names (aliases) for a particular domain. Names of the virtual domains can be specified in the Aliases section. Email addresses within the virtual domains are identical (delivery is performed to the identical mailboxes). If this option is used, individual user accounts can belong to multiple domains.

Usage of domain aliases will be better understood through the following example:

A company uses two domains: company.us and company.com. The company.us domain is was set as a mail domain in Kerio MailServer. Email addresses of the domain users are [email protected]. If we create the company.com domain alias for the company.us domain, it is also possible to use the [email protected] for identical users. It does not matter, whether the [email protected] or the [email protected] is used. In both cases, the mail is delivered to the same user.

Warning: Unless this is a local alias (virtual domain), corresponding MX DNS records must be defined for each of such domains. A simple definition of the domain as an alias of another domain does not make the alias exist in the Internet.

Figure 8.3 Domain settings — equivalent domains (aliases)

8.4 Footers

Domain aliases can be used only for email delivery. It is not possible to use them for user authentication at Kerio MailServer or to view the Free/Busy server. Domain aliases cannot be used for administration purposes.

8.4 Footers

Use this tab to add a footer to each message sent from this domain (footer will be added to each message where the address of the sender includes the domain).

Figure 8.4 Domain settings — footers

Note: The HTML format cannot be used for the footer text. Only plain text is displayed in the message footer.

8.5 Forwarding

Using the Forwarding tab parameters you can forward messages to another SMTP server automatically. Forwarding can be used especially for:

• splitting the domain into more servers (for more information, see chapter25.4),

• creating a backup mailserver (for more information, see chapter25.5).

If the recipient was not found...

Messages will be forwarded to another SMTP server if a recipient is not found in the domain. Messages are forwarded only if the recipient’s address is not an address of any user, group or alias included in this domain. If there is no user, group or alias defined in this domain, all messages will be forwarded (this function is equal to the Forward feature in versions former to Kerio MailServer 5.5).

Chapter 8 Domains

Figure 8.5 Domain settings — forwarding

Forward to server

DNS name or IP address of SMTP server to which all email messages for this domain will be forwarded.

Port

SMTP server port. The Default button sets the standard 25 port.

The forward host is Offline...

Under normal circumstances, Kerio MailServer sends email for the Forward domain to the specified SMTP server immediately. If the server has a dial-up connection to the Internet, then this may cause very often dialing and hanging up of the line (and high costs for the connection). Enabling this option will allow email for the Forward domains to be queued and delivered at scheduled times only (see chapter10).

Queue until triggered by ETRN

Kerio MailServer keeps all messages addressed to this domain up to the moment when the ETRN command with this domain included as a parameter (for details, see chapter16.1) is received before sending them to the defined SMTP server. This way Kerio MailServer can be used as a secondary server for a domain whose primary SMTP server is not permanently connected to the Internet.

If the domain...

Here you can define whether messages that contain one of domain’s aliases in the recipient’s address will be forwarded or not. The Don’t forward such messages option disables loops in case that the particular recipient cannot be found at any server operating with this domain.