The Exim 4.95 mail server has been released, which includes the accumulated fixes and added new features. According to a September automated survey of over a million mail servers, Exim accounts for 58% (57.59% a year ago), Postfix is used on 34.92% (34.70%) of mail servers, Sendmail is 3.52% (3.75%), MailEnable is 2% (2.07). %), MDaemon - 0.57% (0.73%), Microsoft Exchange - 0.32% (0.42%). Main changes:
- Stable support for the fast-ramp message queue processing mode has been announced, which allows you to speed up the start of message delivery when the send queue is large and there are an impressive number of messages directed to typical hosts, for example, when sending a large number of letters to large mail providers or sending through an intermediate message transfer agent (smart host). If the mode is enabled with the "queue_fast_ramp" option and two-stage queue processing ("-qq") detects the presence of a large portion of messages addressed to a specific mail server, then delivery to this host will be started immediately.
- An alternative implementation of the SRS (Sender Rewriting Scheme) mechanism, "SRS_NATIVE", has been stabilized, which does not require external dependencies (the old experimental implementation required the installation of the libsrs_alt library). SRS allows you to rewrite the sender address during transmission without violating the SPF (Sender Policy Framework) checks and ensuring that the sender data is saved for sending by the message server in case of a delivery error. The essence of the method is that when a connection is established, identity information is transmitted with the original sender, for example, when rewriting [email protected] on [email protected] will indicate "[email protected]". SRS is relevant, for example, when organizing the work of mailing lists in which the original message is redirected to other recipients.
- The TLS_RESUME option has been stabilized, providing the ability to resume a previously interrupted TLS connection.
- Stabilized support for the high-performance compact embedded LMDB DBMS that stores data in the key-value format. Only lookup selections from ready-made databases by one key are supported (recording from Exim to LMDB is not implemented). For example, to check the sender domain in rules, you can use a query like "${lookup{$sender_address_domain}lmdb{/var/lib/spamdb/stopdomains.mdb}}".
- Added "message_linelength_limit" option to set a limit on the number of characters per line.
- Provided the ability to ignore the cache when performing lookup requests.
- For the appendfile transport, a quota check is implemented while receiving a message (SMTP session).
- Added support for the "file=" option in SQLite lookup queries. ”, which allows you to specify a database file for a specific operation without specifying prefixes in the line with the SQL command.
- In lookup requests to Lsearch, support for the "ret=full" option has been added to return the entire block of data corresponding to the key, and not just the first row.
- Establishing TLS connections is accelerated by proactively loading and caching information (such as certificates) instead of downloading it before each connection is processed.
- Added "proxy_protocol_timeout" parameter to set the timeout for the Proxy protocol.
- Added parameter "smtp_backlog_monitor" to enable logging information about the size of the queue of pending connections (backlog).
- Added "hosts_require_helo" parameter to disable sending MAIL command unless HELO or EHLO command has been sent before.
- Added the "allow_insecure_tainted_data" parameter, when specified, insecure escaping of special characters in data will result in a warning instead of an error.
- Support for the macOS platform has been dropped (assembly files have been moved to the unsupported category).
Source: opennet.ru