Hello John and thank you for your reply.
I have looked into the plugin you hinted and also the default installed plugins but not activated. I noticed there is a plugin there called 'show_additional_headers' that theoretically should do what i need. I added these 2 lines in the roundcube config file:
//main.inc.php config file entries
$rcmail_config['plugins'] = array('show_additional_headers');
$rcmail_config['show_additional_headers'] = array('x-job');
Here is a sample output of viewsource of a mail with custom headers:
MIME-Version: 1.0
x-job: 447
X-Mailer-LID: 70
X-Mailer-RecptId: 4026507
X: 8
After i activated the plugin, i logged in with the user that received this email, did a refresh, but the cache didn't receive the new parameter( cannot find any x-job or 447 reference in any rows of the mysql table cache).
Is it normal? I cannot figure it out right now if it should affect database cache or not with this plugin.
My other chance is to download, activate the plugin you mentioned, remove the processing part of URLS and tell the plugin to add my custom header(s)? If i login with the users, will the old e-mails be recached and will I find the header info in the database?
I am really stuck here
-Lonwolf