Variable: mh-send-uses-spost-flag
mh-send-uses-spost-flag is a variable defined in mh-comp.el.gz.
Value
nil
Documentation
Non-nil means "send" uses "spost" to submit messages.
If the value of "postproc:" is "spost", you may need to set
this variable to t to tell MH-E to avoid using features of
"post" that are not supported by "spost". You'll know that
you'll need to do this if sending mail fails with an error of
"spost: -msgid unknown".
Source Code
;; Defined in /usr/src/emacs/lisp/mh-e/mh-comp.el.gz
(defvar mh-send-uses-spost-flag nil
"Non-nil means \"send\" uses \"spost\" to submit messages.
If the value of \"postproc:\" is \"spost\", you may need to set
this variable to t to tell MH-E to avoid using features of
\"post\" that are not supported by \"spost\". You'll know that
you'll need to do this if sending mail fails with an error of
\"spost: -msgid unknown\".")