+ telnet <your server> smtp
+ [server sends some sort of "hello" banner]
+ EHLO myhostname
+ [server will probably list a bunch of capabilities]
+ AUTH DIGEST-MD5
+ <copy the gobbledygook that the server sends - this is what I need>
+ *
+ [server says auth aborted]
+ QUIT
+ [server says bye, closes connection]
+
+
+OPTIONAL SMTP AUTH CONFIGURATION
+--------------------------------
+
+In SMTP authentication SquirrelMail uses user's login name and password. If you
+need all users to send mail via an upstream SMTP provider (your ISP, for
+example), and that ISP requires authentication, you can configure custom
+username and password. $smtp_sitewide_user configuration variable stores custom
+username used during SMTP authentication. $smtp_sitewide_pass stores custom
+password that is used during SMTP authentication, if $smtp_sitewide_user
+variable is not empty.
+
+SquirrelMail 1.5.0 and 1.5.1 stored these configuration variables in
+config_local.php. Newer SquirrelMail versions allow to configure them in conf.pl
+configuration utility.
+
+These configuration variables will be used to connect to the SMTP server as long
+as the authentication mechanism is something besides 'none', i.e. 'login',
+'plain', 'cram-md5', or 'digest-md5'.
+
+DEBUGGING SSL ERROR MESSAGES
+----------------------------
+
+SquirrelMail disables display of PHP errors in fsockopen() and
+stream_socket_enable_crypto() function calls. These functions use PHP error
+handler to display connection errors and SquirrelMail tries to handle
+errors without displaying debugging information to end user. If you use TLS or
+STARTTLS and get connection errors, try reproducing them in configtest.php
+script or remove @ symbol from fsockopen() and stream_socket_enable_crypto()
+calls in SquirrelMail scripts.
+
+Possible error messages:
+* SSL: Connection reset by peer in some script.
+ Error happened in IMAP server and server dropped connection. It is possible
+ that error is logged in system or imap logs.
+
+* SSL operation failed with code 1. OpenSSL Error messages: error:14094410:SSL
+routines:func(148):reason(1040) in some script.
+ Error generated by SSL library. Locate numbers listed in 'SSL
+ routines:func(###):reason(####)' string, find ssl.h file in your OpenSSL
+ sources and locate same numbers listed in '/* Error codes for the SSL
+ functions. */' section. Error define can be self explanatory. If you don't
+ understand it, search for error or that define in your favorite search
+ engine.
+