On: Y Combinator’s ReMail Finally Brings Full-Text Email Search To The iPhone

[ankhmoop]

They may be referring to IMAP's server-side search support. If the message isn't cached locally, the IMAP server can search the message headers, body, etc on the phone's behalf.

See RFC 3501, section 6.4.4:

http://www.faqs.org/rfcs/rfc3501.html

[gaborcselle → ankhmoop]

Yup, I believe that's what they're doing. The trouble with this approach is that IMAP servers are painfully slow for server searches. Very few of them build an index. Interestingly, doing searches against Gmail's IMAP is also dog-slow :-(