In a previous article we talked about the launch of SpamAssassin 3.4.3 which is a spam filtering utility and now we are going to talk about Exim, which is a mail carrier (Mail Transport Agent, usually MTA) developed to be used on most Unix systems, including GNU / Linux. East has great flexibility on the paths that messages can follow according to their origin and por introduce functionality for spam control, DNS-based block lists (DNSBL), viruses, relay control, users and virtual domains and others, that are more or less easily configured and maintained.
The project has good documentation, examples of "how to do" certain tasks. Exim is distributed free of charge under the GNU GPL license.
About the new version of Exim 4.93
After 10 months of development, the release of the new version of the Exim 4.93 mail server was announced, in which Cumulative fixes were introduced and new features added.
One of them is the support for external authenticators (RFC 4422). Using the "SASL EXTERNAL" command, the client can inform the server about the use of authentication credentials transmitted through external services, such as IP security (RFC4301) and TLS.
Another added feature is the ability to use JSON format for search checks. Options for "forall" and "any" conditional masks are also added using JSON.
Additionally, new flags have been added to control the reflection of the message identifier in the log (set via the configuration log_selector ): "msg_id»(Enabled by default) with the message identifier and«msg_id_created»With the identifier generated for the new message.
When using OpenSSL, the function of writing files with keys in NSS format has been added to decode intercepted network packets. The file name is set through the SSLKEYLOGFILE environment variable. When compiling with GnuTLS, GnuTLS provides similar functionality, but requires working with root privileges.
You can also find the new variables $ tls_in_cipher_std and $ tls_out_cipher_std that contain the names of the cipher suites corresponding to the RFC name.
Added support for the case_insensitive option to check the "not_blind" mode to ignore the case of characters during verification.
Of the other changes that are announced:
- An experimental option has been added EXPERIMENTAL_TLS_RESUME, which provides the ability to resume a previously interrupted TLS connection.
- Added option exim_version to override a string with the Exim version number displayed in various places and passed through the $ variables exempt_version and $ version_number.
- Added variants of the $ {sha2_N:} operator for N = 256, 384, 512.
- The variables "$ r _ ..." are implemented, which are set from the routing options and are available for use in making decisions about routing and the choice of transport.
- SPF search requests have added IPv6 support.
- When performing checks through DKIM, the ability to filter by type of keys and hashes is added.
- When using TLS 1.3, support is provided for the OCSP (Online Certificate Status Protocol) extension to verify the revocation status of the certificate.
- Added "smtp: ehlo" event to monitor the list of functionalities provided by the remote side.
- Added command line option to move messages from one named queue to another.
- Added variables with TLS versions for incoming and outgoing requests: $ tls_in_ver and $ tls_out_ver.
Finally, the announcement also showed the results of an automated survey from November of approximately one million mail servers, in which Exim's share is 56.90% (56.56% a year ago), Postfix is used on mail servers 34.98 % (33.79%), Sendmail - 3.90% (5.59%), Microsoft Exchange - 0.51% (0,85%).
Download Exim 4.93
To get this new version of Exim 4.93 you must go to its official website in which in its download section you can find the links corresponding to this new version.