paul lesniewski evhqsquirrelmailorg feb 12 2008 637 pm paul lesniewski wrote anyone know top head sm saves sent messages initiating whole new message delivery sequence means messages stored sent folder different message ids receivedby headers date headers name correct headers sent message message sent destination recipient 364 rfc2822 messageid field provides unique message identifier refers particular version particular message uniqueness message identifier guaranteed host generates see message identifier intended machine readable necessarily meaningful humans message identifier pertains exactly one instantiation particular message subsequent revisions message receive new message identifiers note many instances messages changed changes constitute new instantiation message therefore message would get new message identifier example messages introduced transport system often prepended additional header fields trace fields described section 367 resent fields described section 366 addition header fields change identity message therefore original messageid field retained cases meaning sender message wishes convey ie whether message different message determines whether messageid field changes particular syntactic difference appears appear message first paragraph makes think message id presumably headers actually different reading start question although argue officially two instantiations message one gone recipient one sent folder really supposed message meaning marc squirrelmaildevel mailing list list address aqcvnwkdyeemhbpoalistssourceforgenet list archives httpnewsgmaneorggmanemailsquirrelmaildevel list info subscribeunsubscribechange options httpslistssourceforgenetlistslistinfosquirrelmaildevel tue 05 aug 2008 194536 0800 smdevel imap rfc question