In some embodiments, {HEAD ~ a whitelist} such as a whitelist used to hold specific mailing list features, {TAIL ~ a whitelist} used to hold sender/recipient addresses, or a whitelist used to hold sender addresses, may contain hashes of content 
In some embodiments , { HEAD ~ a whitelist } such as a whitelist used to hold specific mailing list features , { TAIL ~ a whitelist } used to hold sender / recipient addresses , or a whitelist used to hold sender addresses , may contain hashes of content
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH