we are using putty to connect the server,no i don't want to send mail from the server
The log files will generate every minute in our server ,it contains lots of contents
like error,warning,alert
we have to copy the alert part from the log file and paste it in our mail for analysis,it will be with huge content and it cross more than 5 pages so we are copying the lines page by page
If you can't use mail or other tools to send a file from a server or use ssh (or other tools) to copy it to your local system (why?) the only way is to copy and paste. You can use "tail -n+700 YOURLOG| head -n200" and copy the content from the putty window.
You execute vi on the server and all buffers are on this server. You can't extract them in any way to your system IMO.
Ok, so your problem isn't vi specific, because your problem would be the same no matter what editor you're using.
And PuTTY does not offer any other way to copy text to the clipboard other than selecting with the mouse. Your best bet would be a sed command to extract the required lines, and pipe that into a mail sent to yourself if possible.