lumisoft mail server中出现“550 5.7.1 Unable to relay for xxx”错误
该错误，在我探索lumisoft mail server源代码的过程中，严重困扰着我，时间长达一周。
幸好，自己还是很有韧性地坚持到找到原因和解决方法。虽然，自己在寻找答案过程中走过很多弯路，但是，在我再坚持一下的努力下，我终于找到答案了，希望对与我遇到相同问题的网友有帮助。
问题：当lumisoft mail server启动后，采用WebMail发邮件会出现“550 5.7.1 Unable to relay for xxx”错误。使用命令行发邮件时，提示" Queued for delivery".
原因：我的IIS中的SMTP默认启动，占用了25端口，导致出现上面的问题。
解决：关闭IIS中的SMTP虚拟服务器，重新启动lumisoft mail server
解决途径：参照了http://www.lumisoft.ee/Forum/default.aspx?g=posts&t=109
IVX的回答
>550 5.7.1 Unable to relay
If you get this, then you run non LS mail server and you have not relay permission, probably IIS smtp is running on port 25.
If you get this, then you run non LS mail server and you have not relay permission, probably IIS smtp is running on port 25.
LS smtp is enabled by default, it probably conficts IIS smtp and wont run.
you may have andy count of smtp servers in 1 computer as long listening IP:port won't conflict.
you may have andy count of smtp servers in 1 computer as long listening IP:port won't conflict.
非常敬佩和感谢IVX！