20.9.2.2 To Set Rules Implementing Automatic Message Removal Policy

To implement the automatic message removal policy defined in the previous section, you must set the imexpire rules. Rules are set by putting them into a store.expirerule file. An example of two global store.expirerule rules is shown below:

Rule1.regexp: 1
Rule1.folderpattern: user/.*/trash
Rule1.messagedays: 2
Rule2:regexp: 1
Rule2.folderpattern: user/.*
Rule2.messagedays: 14

            

In this example, Rule 1 specifies that all messages in the trash folder will be remove after two days. Rule 2 specifies that all messages in the message store will be removed after 14 days.

This section consists of the following subsections:

• Expiration Rules Guidelines

• Setting imexpire Rules Textually

• Setting imexpire Folder Patterns

Expiration Rules Guidelines

This section sets the guidelines for the store.expirerule file rules.

In earlier Messaging Server releases, expiration rules could be set with configutil parameters store.expirerule.attribute (see configutil Parameters in Sun Java System Messaging Server 6.3 Administration Reference.) This is still true, but expire rules using header constraints (example: expiring a message with a specific subject line) are not supported. Also, regular expressions in the expire rules created with configutil need to be POSIX compliant rules. If you want to use UNIX compliant regular expressions you will have to use the store.expire file. In addition, using both configutil options and the global store.expirerule configuration file is not supported. If the configuration file is present, configutil options are not used. In any case, it is best to use store.expirerule to specify all expiration rules.

• Rules are specified in a file called store.expirerule.

• Multiple expiration criteria can be specified with the same rule. (Example above.)

• Rules can apply to the entire message store (global rules), a partition, a user, or a folder.

  • The global rules are stored in msg-svr-base/config/store.expirerule

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    Note –

    Each global rule will be checked against every mailbox, which can cause some processing overhead depending on the number of global rules you specify. For this reason, you should not specify partition, mailbox or user rules in the global rules file. In general, you should try not to put any more expiration rules than necessary in this file.

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  • Partition rules are stored in store_root/partition/partition_name/store.expirerule.

  • User rules are specified in store_root/partition/partition_name/userid/store.expirerule or by specifying the folderpattern rule to be user/userid/.*

  • Folder rules are specified in store_root/partition/partition_name/userid/folder/store.expirerule or by specifying the folderpattern rule to be user/userid/folder

  • Note that multiple non-global rules (user, folder, partition) using rule_name was only implemented in the Messaging Server 6.2p4 release and later.

• Multiple expire rules can be applied to a mailbox at the same time. An expire policy for a mailbox consists of global rules and local rules. Local rules apply to the mailbox under the same directory and all of its sub-folders.

• imexpire unifies all of the expiration rules applying to a mailbox, unless there is an exclusive rule specified for this mailbox (see Table 20–8). The resulting rule set represents the most restrictive expiration policy based on all applicable rules. For example, if rule X expires messages such that the maximum message life is 10 days, and rule Y specifies 5 days, the union will be 5 days.

Localized Mailbox Names

The IMAP protocol specifies that mailbox names use modified UTF-7 encoding. Messaging Server supports localized character sets on external interfaces so that mailbox names can be localized. Internally, however, the system converts the localized name to UTF-7. Thus, a folder that has a localize mailbox name on a client will have a corresponding mailbox file name in UTF-7. (Note that IMAP error messages will output mailbox names in UTF-7 and not the localized character set.)

In general, most message store utilities that require mailbox names expect the names in the localized character set, although they may have an option flag that allows a different character set to be used. These utilities include reconstruct, mboxutil, imsbackup, imsrestore, and hashdir. However, imexpire requires that the mailbox name, specified as the attribute folderpattern,be in UTF-7. Using a localized name will not work.

To obtain the appropriate folderpattern for imexpire it may be necessary to convert a localized mailbox name to the modified UTF-7 equivalent. This can be done using the mboxutil -E command as follows:

The first mboxutil shows the localized filename. The second mboxutil shows the filename in modified UTF-7. It is also possible to use the IMAP list command:

To convert the local charset to modified UTF-7 encoding, use the mboxutil command with the -E option:

Note that mboxutil -E can be used for any command that requires the use of a UTF-7 mailbox name including imexpire.

Setting imexpire Rules Textually

Automatic message removal rules are set by specifying rules in a store.expirerule file. The store.expirerule file contains one expire criteria per line. An expire criteria of the global rule configuration file (msg-svr-base/data/store/store.expirerule) has the following format:

rule_name.attribute: value

An expiration rule for a user or mailbox rule configuration file has this format:

attribute: value

Example 20–4 shows a set of global expiration rules in msg-svr-base/config/store.expirerule.

Rule 1 sets the global expiration policy (that is, policy that applies to all messages), as follows:

• Enable UNIX regular expressions in rules creation.

• Removes messages larger than 100,000 bytes after 3 days.

• Removes messages deleted by the user.

• Removes any message with the strings “Vigara Now!” or “XXX Porn!” in the Subject: header.

• Limits all folders to 1,000 messages. After 1,000 messages, the system removes the oldest messages on a folder to keep the total to 1,000.

• Removes all messages older than 365 days.

Rule 2 sets the automatic message removal policy for users at the hosted domain siroe.com. It limits mailbox sizes to 1 megabyte, removes messages that have been deleted, and removes messages older than 14 days.

Rule 3 sets the automatic message removal policy for messages in the inbox folder of user f.dostoevski. It removes messages with a subject line having the expression “On-line Casino.”

Example 20–4 Example imexpire Rules

Rule1.regexp: 1
Rule1.folderpattern: user/.*
Rule1.messagesize: 100000
Rule1.messagesizedays: 3
Rule1.deleted: or
Rule1.Subject: Vigara Now!
Rule1.Subject: XXX Porn!
Rule1.messagecount: 1000
Rule1.messagedays: 365
Rule2.regexp: 1
Rule2.folderpattern: user/.*@siroe.com/.*
Rule2.exclusive: 1
Rule2.deleted: or
Rule2.messagedays: 14
Rule2.messagecount: 1000
Rule3.folderpattern: user/f.dostoevski/inbox
Rule3.Subject: *On-line Casino*
                  

Setting imexpire Folder Patterns

Folder patterns can be specified using POSIX regular expressions by setting the imexpire attribute regex to 1. If not specified, IMAP expressions will be used. The format must start with a user/ followed by a pattern. Table 20–9 shows the folder pattern for various folders.)