attachment
bdata
cinfo
deleted
deleted_count
dreceived
dsent
flags
folder_name
followup_completed_on
followup_due_by
followup_flag
important
jnd_count
junk
junk_count
labels
mail_cc
mail_from
mail_to
mlist
nextuid
part
preview
read
replied
saved_count
size
subject
time
uid
unknown column name
unread_count
userheaders
usertags
version
visible_count
vuid
An enum of all the known columns, which can be used for a quick column lookups.