To upgrade from MIMEDefang 2.38 to MIMEDefang 2.58, here is what I did after running the INSTALL file over again on my running installation:

1 - I stopped sendmail and mimedefang services.  Otherwise, if a slave ends because it has run through the proper number of uses, I envision many issues during the installation.

2 - I made a backup of /etc/mail/mimedefang-filter just in case

	cp /etc/mail/mimedefang-filter /etc/mail/mimedefang-filter.2.38

3 - I installed MD 2.58 & tried to make the minimal amount of changes to achieve this:

I copied over the latest redhat mimedefang-init and sysconfig

I enabled log_filter_time, mx_embed_perl, changed mx_minimum to 4 and mx_maximum to 10 and I enabled a subfilter in the /etc/sysconfig/mimedefang file.  I’ll enable other things like recipient checks later.

I viewed Changelog in /usr/src/mimedefang-2.58/Changelog from 2.38 UP and searched for INCOMPATIBILITY

Removed message_contains_virus & entity_contains_virus from filter.  Not using filter_relay so didn’t have to change that.

MIMEDefang uses sa-mimedefang.cf in /etc/mail now.  This file is a bit outdated so I usually just blank it out and use /etc/mail/spamassassin/localdb.cf (for database-driven installs).

I don’t use action_add_part so I didn’t have to worry about that change

Removed flatten stupidity config in filter.

added detect_and_load_perl_modules(); to filter

Changed filter_begin prototype to:
sub filter_begin {
my($entity) = @_;

I ran mimedefang.pl –test to make sure the filter was still A-OK.