diff --git a/vc_zoom/indico_vc_zoom/translations/messages.pot b/vc_zoom/indico_vc_zoom/translations/messages.pot
index b3ad8ad..d90908c 100644
--- a/vc_zoom/indico_vc_zoom/translations/messages.pot
+++ b/vc_zoom/indico_vc_zoom/translations/messages.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PROJECT VERSION\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2020-11-25 15:55+0100\n"
+"POT-Creation-Date: 2020-12-03 13:11+0100\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -21,239 +21,294 @@ msgstr ""
 msgid "You are now the host of room '{room.name}'"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:28 indico_vc_zoom/forms.py:61
+#: indico_vc_zoom/forms.py:29 indico_vc_zoom/forms.py:63
 msgid "Passcode visibility"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:29 indico_vc_zoom/forms.py:62
+#: indico_vc_zoom/forms.py:30 indico_vc_zoom/forms.py:64
 msgid "Who should be able to know this meeting's passcode"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:32 indico_vc_zoom/forms.py:65
+#: indico_vc_zoom/forms.py:33 indico_vc_zoom/forms.py:67
 msgid "Everyone"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:33 indico_vc_zoom/forms.py:66
+#: indico_vc_zoom/forms.py:34 indico_vc_zoom/forms.py:68
 msgid "Logged-in users"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:34 indico_vc_zoom/forms.py:67
+#: indico_vc_zoom/forms.py:35 indico_vc_zoom/forms.py:69
+msgid "Registered participants"
+msgstr ""
+
+#: indico_vc_zoom/forms.py:36 indico_vc_zoom/forms.py:70
 msgid "No one"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:44
+#: indico_vc_zoom/forms.py:46
 msgid "Meeting Type"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:45
+#: indico_vc_zoom/forms.py:47
 msgid "The type of Zoom meeting to be created"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:48
+#: indico_vc_zoom/forms.py:50
 msgid "Regular Meeting"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:49 indico_vc_zoom/templates/room_labels.html:4
+#: indico_vc_zoom/forms.py:51 indico_vc_zoom/templates/room_labels.html:4
 msgid "Webinar"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:51
+#: indico_vc_zoom/forms.py:53
 msgid "Meeting Host"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:52
+#: indico_vc_zoom/forms.py:54
 msgid "Myself"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:52
+#: indico_vc_zoom/forms.py:54
 msgid "Someone else"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:54
+#: indico_vc_zoom/forms.py:56
 msgid "User"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:57 indico_vc_zoom/templates/info_box.html:16
+#: indico_vc_zoom/forms.py:59 indico_vc_zoom/templates/info_box.html:18
 #: indico_vc_zoom/templates/manage_event_info_box.html:28
 msgid "Passcode"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:59
+#: indico_vc_zoom/forms.py:61
 msgid "Meeting passcode (min. 8 digits)"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:69 indico_vc_zoom/plugin.py:67
+#: indico_vc_zoom/forms.py:72 indico_vc_zoom/plugin.py:90
 msgid "Mute audio"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:71 indico_vc_zoom/plugin.py:69
+#: indico_vc_zoom/forms.py:74 indico_vc_zoom/plugin.py:92
 msgid "Participants will join the VC room muted by default "
 msgstr ""
 
-#: indico_vc_zoom/forms.py:73 indico_vc_zoom/plugin.py:71
+#: indico_vc_zoom/forms.py:76 indico_vc_zoom/plugin.py:94
 msgid "Mute video (host)"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:75 indico_vc_zoom/plugin.py:73
+#: indico_vc_zoom/forms.py:78 indico_vc_zoom/plugin.py:96
 msgid "The host will join the VC room with video disabled"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:77 indico_vc_zoom/plugin.py:75
+#: indico_vc_zoom/forms.py:80 indico_vc_zoom/plugin.py:98
 msgid "Mute video (participants)"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:79 indico_vc_zoom/plugin.py:77
+#: indico_vc_zoom/forms.py:82 indico_vc_zoom/plugin.py:100
 msgid "Participants will join the VC room with video disabled"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:81 indico_vc_zoom/plugin.py:84
+#: indico_vc_zoom/forms.py:84 indico_vc_zoom/plugin.py:107
 msgid "Waiting room"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:83 indico_vc_zoom/plugin.py:86
+#: indico_vc_zoom/forms.py:86 indico_vc_zoom/plugin.py:109
 msgid "Participants may be kept in a waiting room by the host"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:85 indico_vc_zoom/templates/info_box.html:7
+#: indico_vc_zoom/forms.py:88 indico_vc_zoom/templates/info_box.html:7
 #: indico_vc_zoom/templates/manage_event_info_box.html:8
 msgid "Description"
 msgstr ""
 
-#: indico_vc_zoom/forms.py:85
+#: indico_vc_zoom/forms.py:88
 msgid "Optional description for this room"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:49
-msgid "API Key"
-msgstr ""
-
-#: indico_vc_zoom/plugin.py:51
-msgid "API Secret"
+#: indico_vc_zoom/forms.py:118
+msgid "This user has no Zoom account"
 msgstr ""
 
 #: indico_vc_zoom/plugin.py:53
-msgid "Webhook Token"
+msgid "API Key"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:54
-msgid "Specify Zoom's webhook token if you want live updates"
-msgstr ""
-
-#: indico_vc_zoom/plugin.py:56
-msgid "E-mail domains"
+#: indico_vc_zoom/plugin.py:55
+msgid "API Secret"
 msgstr ""
 
 #: indico_vc_zoom/plugin.py:57
-msgid "Comma-separated list of e-mail domains which can use the Zoom API."
+msgid "Webhook Token"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:59
-msgid "Assistant Zoom ID"
+#: indico_vc_zoom/plugin.py:58
+msgid "Specify Zoom's webhook token if you want live updates"
 msgstr ""
 
 #: indico_vc_zoom/plugin.py:60
+msgid "User lookup mode"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:61
+msgid ""
+"Specify how Indico should look up the zoom user that corresponds to an "
+"Indico user."
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:64
+msgid "E-mail domains"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:66
+msgid ""
+"List of e-mail domains which can use the Zoom API. Indico attempts to "
+"find Zoom accounts using all email addresses of a user which use those "
+"domains."
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:70
+msgid "Indico identity providers"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:72
+msgid ""
+"Identity providers from which to get usernames. Indico queries those "
+"providers using the email addresses of the user and attempts to find Zoom"
+" accounts having an email address with the format username@enterprise-"
+"domain."
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:77
+msgid "Enterprise domain"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:79
+msgid ""
+"The domain name used together with the usernames from the Indico identity"
+" provider"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:82
+msgid "Assistant Zoom ID"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:83
 msgid ""
 "Account to be used as owner of all rooms. It will get \"assistant\" "
 "privileges on all accounts for which it books rooms"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:63
+#: indico_vc_zoom/plugin.py:86
 msgid "Allow Webinars (Experimental)"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:65
+#: indico_vc_zoom/plugin.py:88
 msgid "Allow webinars to be created through Indico. Use at your own risk."
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:79
+#: indico_vc_zoom/plugin.py:102
 msgid "Join Before Host"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:81
+#: indico_vc_zoom/plugin.py:104
 msgid ""
 "Allow participants to join the meeting before the host starts the "
 "meeting. Only used for scheduled or recurring meetings."
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:88
+#: indico_vc_zoom/plugin.py:111
 msgid "Creation email footer"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:89
+#: indico_vc_zoom/plugin.py:112
 msgid "Footer to append to emails sent upon creation of a VC room"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:91
+#: indico_vc_zoom/plugin.py:114
 msgid "Send host URL"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:93
+#: indico_vc_zoom/plugin.py:116
 msgid ""
 "Whether to send an e-mail with the Host URL to the meeting host upon "
 "creation of a meeting"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:233
+#: indico_vc_zoom/plugin.py:122
+msgid "Invalid identity providers: {}"
+msgstr ""
+
+#: indico_vc_zoom/plugin.py:272
 msgid "No Zoom account found for this user"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:235
-msgid "Problem getting information about Zoom account"
+#: indico_vc_zoom/plugin.py:273
+msgid "Problem setting Zoom account assistants"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:302
+#: indico_vc_zoom/plugin.py:338
 msgid ""
 "Could not create the room in Zoom. Please contact support if the error "
 "persists"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:331
+#: indico_vc_zoom/plugin.py:365
 msgid ""
 "Can't get information about user. Please contact support if the error "
 "persists."
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:338
+#: indico_vc_zoom/plugin.py:372
 msgid "This user doesn't seem to have an associated Zoom account"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:402
+#: indico_vc_zoom/plugin.py:442
 msgid "Room didn't existing in Zoom anymore"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:405
+#: indico_vc_zoom/plugin.py:445
 msgid "Problem deleting room"
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:461
+#: indico_vc_zoom/plugin.py:520
 msgid ""
 "There are one or more scheduled Zoom meetings associated with this event "
 "which were not automatically updated."
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:464
+#: indico_vc_zoom/plugin.py:523
 msgid ""
-"There are one or more scheduled Zoom meetings associated with "
-"contribution '{}' which  were not automatically updated."
+"There are one or more scheduled Zoom meetings associated with the "
+"contribution \"{}\" which  were not automatically updated."
 msgstr ""
 
-#: indico_vc_zoom/plugin.py:467
+#: indico_vc_zoom/plugin.py:526
 msgid ""
 "There are one or more scheduled Zoom meetings associated with this "
 "session block which were not automatically updated."
 msgstr ""
 
-#: indico_vc_zoom/util.py:74
+#: indico_vc_zoom/util.py:39
+msgid "Email domains"
+msgstr ""
+
+#: indico_vc_zoom/util.py:40
+msgid "Authenticators"
+msgstr ""
+
+#: indico_vc_zoom/util.py:116
 msgid "This room has been deleted from Zoom"
 msgstr ""
 
-#: indico_vc_zoom/util.py:78
+#: indico_vc_zoom/util.py:120
 msgid ""
 "Problem fetching room from Zoom. Please contact support if the error "
 "persists."
 msgstr ""
 
-#: indico_vc_zoom/util.py:97
+#: indico_vc_zoom/util.py:139
 msgid "Can't update meeting. Please contact support if the error persists."
 msgstr ""
 
@@ -265,23 +320,49 @@ msgstr ""
 msgid "Make me host"
 msgstr ""
 
-#: indico_vc_zoom/templates/buttons.html:22
-#: indico_vc_zoom/templates/buttons.html:28
+#: indico_vc_zoom/templates/buttons.html:24
+#: indico_vc_zoom/templates/buttons.html:30
 msgid "Join"
 msgstr ""
 
-#: indico_vc_zoom/templates/buttons.html:26
+#: indico_vc_zoom/templates/buttons.html:28
 msgid "You will need a passcode to join this Zoom meeting"
 msgstr ""
 
-#: indico_vc_zoom/templates/buttons.html:32
+#: indico_vc_zoom/templates/buttons.html:36
+#: indico_vc_zoom/templates/buttons.html:42
+#: indico_vc_zoom/templates/buttons.html:48
+msgid "This Zoom Meeting can only be seen by registered participants"
+msgstr ""
+
+#: indico_vc_zoom/templates/buttons.html:38
+msgid "Please register"
+msgstr ""
+
+#: indico_vc_zoom/templates/buttons.html:43
+msgid "Registration required"
+msgstr ""
+
+#: indico_vc_zoom/templates/buttons.html:50
+msgid "Please log in and register"
+msgstr ""
+
+#: indico_vc_zoom/templates/buttons.html:55
 msgid "This Zoom Meeting can only be seen by logged in users"
 msgstr ""
 
-#: indico_vc_zoom/templates/buttons.html:34
+#: indico_vc_zoom/templates/buttons.html:57
 msgid "Please log in"
 msgstr ""
 
+#: indico_vc_zoom/templates/extra_delete_msg.html:2
+#, python-format
+msgid ""
+"The host of this Zoom meeting is <strong>%(host)s</strong>. In case you "
+"want to delete this Zoom meeting from all events, please make sure that "
+"they do not use it for other events that may still need it!"
+msgstr ""
+
 #: indico_vc_zoom/templates/info_box.html:4
 #: indico_vc_zoom/templates/manage_event_info_box.html:5
 msgid "Zoom Meeting ID"
@@ -292,7 +373,7 @@ msgstr ""
 msgid "Host"
 msgstr ""
 
-#: indico_vc_zoom/templates/info_box.html:20
+#: indico_vc_zoom/templates/info_box.html:22
 #: indico_vc_zoom/templates/manage_event_info_box.html:30
 msgid "Zoom URL"
 msgstr ""