I have discovered the following parameters through trial and error.
/emailsendattachment <string1> <string2> <int1> <int2> <int3> <string3>
string1 = global name of the recipient.
string2 = subject field of the email
int1 = the amount of influence/infamy to attach
int2 = a type code : (2=inspiration, 5=enhancement, 11=salvage, recipes is still unknown)
int3 = the inventory location of the type: (0=lower left inspiration or the leftmost enhancement, or the first salvage in the inventory list)
string3 = message body
Example:
/emailsendattachment @apparition gifts 1000000 2 3 here you go.
will send an email to @apparition with the subject of gifts, 1000000 inf, the 4th inspiration from the inspiration tray and the message "here you go."
If anyone finds the type code for recipes please let me know.