Three utility programs are provided for maintaining the DBM files that Exim uses to contain its delivery hint information. Each program requires two arguments. The first specifies the name of Exim's spool directory, and the second is the name of the database it is to operate on. These are as follows:
the database of retry information
the database of information about rejected messages
the database of information about messages waiting for SMTP hosts
the database of information about current connections to hosts which are restricted to one connection at once
The entire contents of a database are written to the standard output by the exim_dumpdb program, which has no options or arguments other than the spool and database names. For example, to dump the retry database:
exim_dumpdb /var/spool/exim retry
31-Oct-1995 12:00:12 02-Nov-1995 12:21:39 02-Nov-1995 20:21:39 * The first item on the first line is the key of the record. It starts with one of the letters D, R, or T, depending on whether it refers to a directing, routing, or transport retry. For a local delivery, the next part is the local address; for a remote delivery it is the name of the remote host, followed by its failing IP address. Then there follows an error code, an additional error code, and a textual description of the error.
The three times on the second line are the time of first failure, the time of the last delivery attempt, and the computed time for the next attempt. The line ends with an asterisk if the cutoff time for the last retry rule has been exceeded.
Each output line from exim_dumpdb for the reject database consists of a date and time, followed by the letter T or F, followed by the address that was rejected, followed by the name of the host that sent the bad address (as given in the SMTP HELO command). The letter is F if only one previous rejection of this address has been done recently, and T if a second has occurred, causing rejection of the MAIL FROM command, and subsequently rejection of the RCPT TO commands.
Each output line from exim_dumpdb for the wait-smtp database consists of a host name followed by a list of ids for messages that are or were waiting to be delivered to that host. If there are a very large number for any one host, continuation records, with a sequence number added to the host name, may be seen. The data in these records is often out of date, because a message may be routed to several alternative hosts, and Exim makes no effort to keep cross references.
Each output line from exim_dumpdb for the serialize-wmtp database consists of a host name preceded by the time that Exim made a connection to that host. Exim keeps track of connections only for those hosts or networks that have been configured for serialization.
The exim_tidydb utility program is used to tidy up the contents of the databases. If run with no options, it removes all records from a database that are more than 30 days old. The cutoff date can be altered by means of the -t option, which must be followed by a time. For example, to remove all records older than a week from the retry database:
exim_tidydb -t 7d /var/spool/exim retry
For the wait-smtp database , the -f option can also be used (it has no effect for other databases). This causes a check to be made to ensure that message ids in database records are those of messages that are still on the queue. Other message ids are removed, and if this leaves records empty, they are also removed.
The exim_tidydb utility outputs comments on the standard output whenever it removes information from the database. It is suggested that it be run periodically on all three databases, but at a quiet time of day, since it requires a database to be locked (and therefore inaccessible to Exim) while it does its work.
The exim_fixdb program is a utility for interactively modifying databases. Its main use is for testing Exim, but it might also be occasionally useful for getting round problems in a live system. It has no options, and its interface is somewhat crude. On entry, it prompts for input with a __
If 'd' is typed at the next prompt, the entire record is deleted. For the reject, wait-smtp, and serialize-smtp databases, that is the only operation that can be carried out. For the retry database, each field is output preceded by a number, and data for individual fields can be changed by typing the field number followed by new data, for example: