One idea runs through every word here: sending something out. Send a person and you get the shaliach, the emissary. Send a parcel and you get the mishloach, the shipment. Send out an arm and you get something stretched out; send out a team and you get a delegation. The root reaches outward in every form. Every word here is verified against pealim, niqqud included.
The same root runs through the verb system. Each binyan is a voice: it bends the one idea into active, passive, causative or reciprocal. Tap to hear.
Notice the drift: pa'al simply sends, pi'el sends away with force (release, dismiss), and hitpa'el turns that force loose on a person (to lash out). The hif'il and pu'al are not lexicalized for this root.
Same root letters, different noun moulds (mishkalim). The mould tells you the function: who does it, the act of doing it, or the thing produced.
Strip the prefixes, suffixes and vowels. Three consonants remain, and the meaning lives there.