add postfix version check

add stress adaptive behavior (syntax changes with postfix version 3.0)

add smtpd_relay_restrictions (postfix version 2.10)

Enhancements on German translation files (Ported from !523)

See merge request ispconfig/ispconfig3!1108

Change remote upgrade to apt-get (#4397)

See merge request !1107

Create Junk-Folder if it doesn't exist, but Junkmail shall be moved

See merge request ispconfig/ispconfig3!1100

Add form element for jailkit_chroot_authorized_keys_template #4901

See merge request ispconfig/ispconfig3!1096

Address "GoAccess errors in log"

Closes #5689

See merge request ispconfig/ispconfig3!1095

Implements #4561: SHA256 (ECDSAP256SHA256) Algorithm for DNNSEC and Algorithm...

Closes #4561

See merge request ispconfig/ispconfig3!1089

Add ui setting for client protection mode

Closes #4048

See merge request ispconfig/ispconfig3!1088

Implements #5400 Prevent that domains with server_id 0 can be added

Closes #5400

See merge request ispconfig/ispconfig3!1099

Fixed Column 'sys_userid' cannot be null error when adding website as admin without choosing a client.

Change loglevel to debug if no DB exists for site (#5688)

Closes #5688

See merge request ispconfig/ispconfig3!1093