Indexing Mail faster

[Kevin Laurie]

Hi,
I am trying to get faster search results on our webmail client(Roundcube).
Besides using Lucene for FTS are there other options?
Would having all mails indexed give fast results?
Currently the time it takes to search 25,000mails is 4mins. If indexed how
much faster are we looking at?
Really appreciate if someone could advise about this.
Thanks
Kevin