ipurge -s option?

[+archive.info-cyrus at utdallas.edu]

What about the following?  I was thinking it might be nice if ipurge
had a -s option for skipping "special" messages.  That is, if you
flag certain messages as special[*], then run ipurge -s on that
folder, these flagged messages would not be deleted even if they
otherwise matched the criteria for being removed.  Thoughts?

Amos

*-- some clients refer to flagged messages as "special" or
    "important". I'm not sure if there's an official name for this.