since that is the only file we're reading in this function.
For some unkonwn reason, opening mail.sdt can sometimes take as long
as 2-3 seconds when the file is on a SMB/CIFS share. This could cause calls to
getmail() to stall noticeably (e.g. sbbsctrl, with the Statistics windows
visible) and logging into the terminal server or viewing user statistics. This
is a new problem, perhaps only with Vertrauen, but this optimization helps
to eliviate the most obvious performance problems triggered by it.
Better/safer string modification (e.g. use of SAFEPRINTF).