[CentOS] Problems with Server and Mail server

[Feizhou]

> I think it may be a access permition issue, but this happens from one 
> day to another, and in at least 3 linux machines... so, where can i look 
> for solution in my server?

First, you need to identify the problem. Start with logs.

> 
> Other thing is the mail server (outgoing) doesn't work, when i try to 
> send a mail through the mail server (the same file server machine), it 
> search for the outgoing server (192.168.0.10) and can't establish 
> connection.  A linux user friend told me to shutdown the machine and 
> disconect the power cord for a minute and then restart the system.  It 
> worked for a time, but then it start the same problem and can only be 
> solved by shooting down the system, and that is a bad solution.  The 
> mail server use to work fine, 24/7.

What are you using for your mail server and what do the logs say?

> 
> These 2 problems start when a electric crash burned out the router, and 
> then when i replaced it  the start to  happen, but router configuration 
> is fine and doesn't seem to have a problem.
> 
> Please help me to identify or solve the problem. Thanks everyone
> 

Check logs.