is there any Android email app with advanced searching capability?

I installed "Maildroid" several months ago, as I needed an app that supported "reply-to" and it was the only one I found. Since then, I have really come to appreciate the features, such as the encryption plug in. The search features are very good like in Thunderbird. Thunderbird has kind of pissed me off, every time they update, most of my plug ins become unusable, but I digress. Anyway, I think Maildroid has a free version with ads, but I bought it, it was only a couple bucks if I recall.

 

Nine, which was originally written for Exchange accounts but can handle imap too, has that type of search capability. It is a paid app with a trial period, but as I hate ads and don't expect developers to work for nothing that's my preferred type.