Unexplained mutt error

[Ion]

New user. Gecko Linux O.S.

My incoming mail goes to pobox.com and is redirected to ionmich at eml.cc.
It shows up in mutt. My outgoing mail is sent to smtp.pobox.com. This
method works...

Code:
:~> echo "" | mutt -s "subject" -i file.txt  ionmich at gmx.us

...while executing mutt and using the menus, with the same addresses
leaves me with...

Code:
CREATE failed: Permission denied

Same .muttrc for both.

This is my home directory .muttrc file...

Code:
set imap_user=ionmich at eml.cc
set imap_pass="my eml password"
set realname    ="Ion"
set from = "ion at pobox.com"
set folder=imaps://mail.messagingengine.com
set smtp_url ="smtp://ion@pobox.com@smtp.pobox.com:587"
set smtp_pass = "my pobox password"
set ssl_force_tls =yes
set header_cache = ~/.cache/mutt
set spoolfile = "+INBOX"
set record ="+Sent"
set postponed="+Drafts"
set trash = "+Trash"
set editor ="nano"
set timeout=15
set mail_check=1
set check_new=yes
auto_view text/html

I have checked the permissions on all related files.