First off, you really should talk to your Lotus administrator. If your company does not have one, you should get one or hire a consultant.
Normally, the email design for all mail files is set to match the version of the Domino server. This is normally done across the board for all users in the company. It is normally done by an administrator since they are the only ones who understand how changing the design will affect your organization.
That said...
RE: "How does the mail file look like. Is it the mail\kl\vcjcal26.nsf file?"
It is not possible to tell from a file path. The fact that it is in a folder named 'mail' suggests that it is a mail file, but does not guarantee it.
RE: "Can i copy the design template on the server and paste it and change name to 'StdR85Mail'?"
I don't understand this question. The design template name is a database property (File > Application > Properties, 4th tab, Inherit design from master template, Template Name). You just type the template name (StdR85Mail) in the Template Name field, then refresh the design (File > Application > Refresh Design...).
RE: "Will it be applicable to only my account or will it change for everyone on the server?"
If you upgrade the design or your own mail file, it will not affect other users' mail files. However, if you are using a shared mail file, then yes, it will affect the other users of the shared mail file.
Personally, I do not allow my users to change the design of their mail files. I have them all setup as Editors, so they do not have enough access to do so. As an administrator, I would be foolish to allow someone to introduce new code on my servers without my knowledge. In fact, I have processes running on the server that detects mail files that do not match our companies approved design. I don't want to get you into any hot water, so again I'll recommend (strongly) that you contact your Lotus administrator before trying any of this.
