今天把postfix升级到2.3.0 之前2.2.10一直使用很好，当然还是按以前的编译方式，但却发现smtp不正常，察看log显示以下错误
Jul 24 14:58:46 wap postfix/smtpd[15000]: warning: unsupported SASL server implementation: cyrus
Jul 24 14:58:46 wap postfix/smtpd[15000]: fatal: SASL per-process initialization failed
Jul 24 14:58:47 wap postfix/master[14946]: warning: process /usr/libexec/postfix/smtpd pid 15000 exit status 1
Jul 24 14:58:47 wap postfix/master[14946]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling
好生觉得奇怪，察看2.3.0的Change log ，找到原因，原来编译的时候必须加一个参数，英文是这么写的
[Incompat 20051220] The Postfix-with-Cyrus-SASL build procedure has
changed. You now need to specify -DUSE_CYRUS_SASL in addition to
-DUSE_SASL_AUTH or else you end up without any Cyrus SASL support.
The error messages are:
unsupported SASL server implementation: cyrus
unsupported SASL client implementation: cyrus
增加-DUSE_CYRUS_SASL 这个编译参数后，重新编译，测试通过