With BlueMail you can easily search by tapping the Magnifying Glass icon in the top bar icon, to locate specific emails using keywords.
Our search looks for your query string in a given folder you are currently viewing, and looks for both client downloaded and server emails ("old" emails in that folder).
To find emails on server, go to the Unified account | type your keyword in the search | when prompted with results choose the account on which you wish to further search on server from the bottom.
We search your subject, body, and recipients so you can use words from any of those fields to find your emails.
Once you get search results you can tap to see a specific mail, or long tap to multi edit and perform actions on some or all of the results. See more in Multi-Edit