git checkout -B maint3

add to ChangeLog:
--- begin
#!!! This is the maintenance version of this module.  When you start fresh,
#!!! go for version 4 (or higher).  On github, this code is branch 'maint3'
#!!! Convert? See F<https://github.com/markov2/perl5-Mail-Box/wiki/>

version 3.01:

    Changes:
    - maintenance release with Mail::Box version 3 compatibility.
---end

add to the DESCRIPTION of the main package module:

--begin
B<This is a maintenance release for the old interface>.  Read
F<https://github.com/markov2/perl5-Mail-Box/wiki/> how
to move towards version 4.
--end

Makefile.PL
  check: dependencies to MailBox most be <4.0

git commit -a
git push --set-upstream origin maint3
git pull
../oorelease

######### version 4.000

git checkout master

add to ChangeLog:
--- begin
#!!! Mail::Box 3 compatibility is still maintained on github in branch
#!!! maint3, and published.  So: you may find newer versions with major
#!!! number 3.  Use (at least) version 4 for new developments.
#!!! Convert? See https://github.com/markov2/perl5-Mail-Box/wiki/

version 4.000:

    Changes:
    - use Mail::Box 4 exception model: use Log::Report

--- end

README.md section "Installing":
--begin
**Be aware that version 4 is not fully compatible with releases pre-4**
See <https://github.com/markov2/perl5-Mail-Box/wiki/>
--end

add to the DESCRIPTION of the main package module:
--begin
B<Be aware:>
This module versions 4.0 and up is not fully compatible with older releases:
mainly the exception handling has changed.  When you need to upgrade, please
read F<https://github.com/markov2/perl5-Mail-Box/wiki/>
B<Version 3 is still maintained> and may see new releases as well.
--end

Makefile.PL:
   upgrade minimal dependencies to the MODULES to '4.0'
   VERSION = '4.000';
   add to requires:
         'Log::Report'      => 1.42,
   remove dependency to Carp

vi $(find lib -name \*pm)
   use base -> use parent
   use Log::Report 'domain';
   remove 'or return' on most SUPER::
   remove Carp
   remove log() and logSettings()
   remove die/warn
   error etc start with lower-case
   error, warning ends on '.'
   grep -rE '\b(die|warn|cluck|carp|croak|confess|Carp|SUPER::|log|base)\b' lib

   "tests in"

***** MODULES

HTML-FromMail           done
Mail-Box
Mail-Box-IMAP4          done
Mail-Box-POP3           done
Mail-Box-Parser-C
Mail-Message
Mail-Transport          done
Object-Realize-Later    done
User-Identity           done

# MailTools
# MIME-Types
