SOS-Linux server- how can i change IP of smtp
I have a simple Linux server connected to the internet with a static IP address.
all users without any limitation can:1-use internet 2-save/modify/delete files on server 3-can send/receive emails using Mozilla Thunderbird (IMAP mail server-outgoing server SMTP)
My internet connection was slow, so I made a new contract.I simply plugged the new line to the server and I realized that all the users can happily use internet and can receive email, BUT they cannot send email!
I also realized that in Thunderbird>Account Setting>Outgoing Server SMTP>edit in Server Name is still the old IP address, so I changed it to the new IP; But it dosn't work and Thunderbird give an error saying that he cannot find SMTP blablabla
I was informed that I must access to the Linux server and change the IP inside the server... I downloaded PuTTY and Login with port 22 and then password...Now I see a frightening black screen with rootAToffice:~# , would you please tell me what should I do? I do not know any command of linux, so how can I do that?