While we are talking about greatest features and GMail... it would be awfully nice if they would finally implement some sort of sub-string search, given it's almost 2013 and they are synonymous with searching and finding things on the internet.
It is incredibly frustrating that in order to be able to find an email I received years ago I have to figure out exactly how someone might have written a certain term in that mail. And I cannot see any excuse for not offering that feature; limit me to a few substring searches a day if resources are an issue and I don't expect fully-indexed lightning-fast results, a simple "grep", so to speak, would be just fine...but please let me search my mails properly!
Even though sub-string search is a slightly offtopic for this post I'll go on with this.
As a native Finn it's quite hard to use Gmail search for anything in our native language.
Just an example. If I want to search for, as an example, invoices (which many companies send directly to your email) I simply cannot do it.
The reason is this:
"Tässä laskunne" - "Here is your invoice"
"Saitte laskun" - "You've received an invoice"
"Puhelinlasku" - "Mobile bill" (the monthly invoice)
The word for invoice in Finnish is "lasku". And there are immense amount of ways to morph the word. And that is with every word. So in order to search for those kinds of mails we usually just search in the basic form. In GMail it's impossible so it's a pure guessing game.
I think this shows nicely that when developing something and thinking "This feature is not really needed" you might accidentally ruin the whole main feature for use cases you're not familiar with.
I use Opera for this. It is set to periodically fetch my mails from Gmail and I do not use its builtin mailer to send/receive/read mails (I use the web interface for that), but if I need a substring search then I open the Opera mail search panel and it allows me to dig through my past mail with substring search.
Edit: maybe it is doing prefix search only (I dont' know I search prefixes usually), so it's no true substring search, but prefix search is very useful in itself.
It is incredibly frustrating that in order to be able to find an email I received years ago I have to figure out exactly how someone might have written a certain term in that mail. And I cannot see any excuse for not offering that feature; limit me to a few substring searches a day if resources are an issue and I don't expect fully-indexed lightning-fast results, a simple "grep", so to speak, would be just fine...but please let me search my mails properly!