CentOS - Sep 2020 - Conversion from Centos 5 to Centos 7 & mailx changes

Everyone,

I have just upgraded a Centos 5 server to a Centos 7 server and am
having difficulty with a change of behavior of mailx with the use of a
command line of :

mail -s 'This is the subject' user at domain.com < text_file.txt

On Centos 5 when mailx was used by a program started by a cron job we
were able to send a text file as an email message and the headers did
not contain 'Content-Transfer-Encoding: base64'

On Centos 7 the headers contain 'Content-Transfer-Encoding: base64' and
when the client gets the e-mail they are unable to open it up.

The interesting thing is that on Centos 7 when the command line is used
by typing the above command 'Content-Transfer-Encoding: 7bit' is placed
in the header and the client can see the e-mail without a problem.

I have looked for a way to control the 'Content-Transfer-Encoding:'
header to '7bit' when we use a cron job, but I have not been able to
figure out how.

Your suggestions would be appreciated.

Thank you,
-- 
Greg Ennis

On Fri, 4 Sep 2020 at 16:00, Gregory P. Ennis <PoMec at pomec.net> wrote:
> Everyone,
>
> I have just upgraded a Centos 5 server to a Centos 7 server and am
> having difficulty with a change of behavior of mailx with the use of a
> command line of :
>
> mail -s 'This is the subject' user at domain.com < text_file.txt
>
> On Centos 5 when mailx was used by a program started by a cron job we
> were able to send a text file as an email message and the headers did
> not contain 'Content-Transfer-Encoding: base64'
>
>
The version of mailx in Red Hat Enterprise Linux 5 is based off the old BSD
mailx program (in Debian it looks like it is still available as bsd-mailx).
That version was 'bit' rotting and having problems with newer mail
servers.  For an afternoon read
http://heirloom.sourceforge.net/mailx_history.html and
https://www.redhat.com/archives/rhl-devel-list/2008-June/msg00628.html [It
looks like this was further forked into s-nail which Debian, Ubuntu, Arch,
etc seem to ship as the default for mailx now.]

Looking for why this change was done I found these:

https://www.redhat.com/archives/rhl-devel-list/2008-June/msg00632.html
https://www.redhat.com/archives/rhl-devel-list/2008-June/msg00641.html

which says one of two ways to hack around this problem:
1. Put in /etc/mail.rc the items needed
2. Try the MAILRC=/dev/null hack

and finally a google "heirloom mailx Content-Transfer-Encoding base64"
got
me to

https://stackoverflow.com/questions/10343106/linux-mail-file-log-has-content-type-application-octet-stream-a-noname-attac


which seems to offer changing it to

cat -v {{file}} | mail -s "your subject" "your at
recipient.internet"



> On Centos 7 the headers contain 'Content-Transfer-Encoding: base64'
and
> when the client gets the e-mail they are unable to open it up.
>
> The interesting thing is that on Centos 7 when the command line is used
> by typing the above command 'Content-Transfer-Encoding: 7bit' is
placed
> in the header and the client can see the e-mail without a problem.
>
> I have looked for a way to control the 'Content-Transfer-Encoding:'
> header to '7bit' when we use a cron job, but I have not been able
to
> figure out how.
>
> Your suggestions would be appreciated.
>
> Thank you,
> --
> Greg Ennis
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
>

-- 
Stephen J Smoogen.

--On Friday, September 04, 2020 3:58 PM -0500 "Gregory P. Ennis" 
<PoMec at PoMec.Net> wrote:
> On Centos 7 the headers contain 'Content-Transfer-Encoding: base64'
and
> when the client gets the e-mail they are unable to open it up.
That sounds like a broken client that needs to be updated. What kind of 
client?

Stephen and Kenneth,

Thank you very much for your help.

I tried 'MAILRC=/dev/nul' which I put in /etc/mail.rc as

'set MAILRC=/dev/null'

But I did not identify that this changed any behavior.

The link below was very helpful Stephen thank you for your kindness in digging
this out for
me.
https://www.digitalocean.com/community/tutorials/how-to-send-e-mail-alerts-on-a-centos-vps-for-system-monitoring

In the end the above link gave me a grammar and syntax that worked, but it is
requiring a
change in every line of code that the 'mail' command had been used.  the
following syntax
and grammer gave me what I needed.

echo | mail -s "Subject" -r from at address -q /loc/to/body.txt email
at address

Thank you again for your help!!!

Greg