Not getting any new mail

["James Dunleavy" <purpletenspeed@xxxxxxxxx>]

For some reason mutt is unable to download new mail once the program
is open.  It will download new mail when mutt is first launched and
initialized, however I get an error message "Mailbox was externally
modified.  Flags may be wrong"

My muttrc file is listed bellow.

Any help in fixing this would be greatly appreciated!

Thanks
James

set spoolfile=imap://exchange.hq.domain.com/INBOX
set imap_user=username
set folder=imap://exchange.hq.domain.com/  # Point to IMAP server
set record="=Sent Items"

set header_cache=~/.hcache
set envelope_from=yes
set editor="pico"
set sendmail="/usr/sbin/ssmtp"

set move = no

set edit_headers=no
set autoedit

mailboxes =imap://exchange.hq.domain.com/INBOX


set sort=threads

set index_format='%4C %Z %d %-20.20F %?M?-->%3M&(%4l)? %s'

# Date format
set date_format = "%d/%m/%y %H:%M"

## Headers ##
#

# Show only
ignore *
unignore Subject: Date: From: Reply-To: To: CC: BCC: X-Mailer: User-Agent:

# In this order
unhdr_order *
hdr_order From: To: Reply-To: CC: BCC: Date: Subject:


## Pager ##
#

# Stop at the end of a message
set pager_stop

# Always show n line of the pager
set pager_index_lines = 5

# Preserve context (ala slrn) of multi-paged messages
set pager_context = 1

# Show ~ sign like Vi
set tilde

# Wrap long lines
#set wrap =80

## Attachment ##
#



# Check mail every 30 seconds
set mail_check=90

# search for new messages in folders
set check_new

# Wait 15 second of idle time before updating status
set timeout=15

#imap_check_subscribed=yes