I-K-9 Mail uhlelo lokusebenza lwe-imeyili oluzimele lohlelo lokusebenza lwe-Android. Yenziwa itholakale njenge-Free/Open Source Android Software ngaphansi kwelayisensi ye-Apache-2.0. Uhlelo lukhangiswa njengendlela esebenza kangcono yokumiselela i-imeyili ezenzakalelayo efakwe kumafoni amaningi. Isekela kokubili amabhokisi eposi we-POP3 ne-IMAP futhi isekela i-IMAP IDLE ukuze uthole izaziso zesikhathi sangempela.