diff --git a/README.md b/README.md
index 33a05c43..ca0bfe0d 100644
--- a/README.md
+++ b/README.md
@@ -167,6 +167,21 @@ INVITE_FROM_ADDRESS=no-reply@example.org
 > If the username, password or host contain any character considered special in a URI (such as `: / ? # [ ] @ ! $ & ' ( ) * + , ; =`), you MUST encode them.
 > See [here](https://symfony.com/doc/current/mailer.html#transport-setup) for more details.
 
+If `INVITE_FROM_ADDRESS` is empty, Davis does not send scheduling emails at all and logs a warning when the DAV endpoint starts.
+
+Invitations are only produced for events whose `ORGANIZER` matches the organiser's own address, and that address is the `email` of their principal — the *Email* field of the account in the dashboard. If it is empty or different from what the calendar client sends, the server has nothing to send an invitation about and stays silent. To find accounts in that state:
+
+```sql
+SELECT uri, email FROM principals WHERE email IS NULL OR email = '';
+```
+
+To check the mailer itself without creating an event:
+
+```shell
+php bin/console davis:mail:test you@example.org
+```
+
+
 **f. The reminder offset for all birthdays**
 
 You must specify a relative duration, as specified in [the RFC 5545 spec](https://www.rfc-editor.org/rfc/rfc5545.html#section-3.3.6)
diff --git a/config/services.yaml b/config/services.yaml
index 25662b12..6fa8da2f 100644
--- a/config/services.yaml
+++ b/config/services.yaml
@@ -30,6 +30,10 @@ services:
         arguments:
             $authRealm: "%env(AUTH_REALM)%"
 
+    App\Command\MailTestCommand:
+        arguments:
+            $inviteAddress: "%env(INVITE_FROM_ADDRESS)%"
+
     App\Services\IMAPAuth:
         arguments:
             $IMAPAuthUrl: "%env(IMAP_AUTH_URL)%"
diff --git a/src/Command/MailTestCommand.php b/src/Command/MailTestCommand.php
new file mode 100644
index 00000000..8073d749
--- /dev/null
+++ b/src/Command/MailTestCommand.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace App\Command;
+
+use Symfony\Component\Console\Attribute\AsCommand;
+use Symfony\Component\Console\Command\Command;
+use Symfony\Component\Console\Input\InputArgument;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
+use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
+use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mime\Address;
+use Symfony\Component\Mime\Email;
+use Symfony\Component\Mime\Exception\RfcComplianceException;
+
+/**
+ * Invitations are sent while a calendar client is storing an event, so a broken MAILER_DSN shows
+ * up as a missing email and nothing else. This sends one message with the same settings.
+ */
+#[AsCommand(
+    name: 'davis:mail:test',
+    description: 'Send a test email to check MAILER_DSN and INVITE_FROM_ADDRESS',
+)]
+class MailTestCommand extends Command
+{
+    public function __construct(
+        private MailerInterface $mailer,
+        private ?string $inviteAddress = null,
+    ) {
+        parent::__construct();
+    }
+
+    protected function configure(): void
+    {
+        $this
+            ->addArgument('to', InputArgument::REQUIRED, 'The address to send the test email to')
+            ->setHelp('This command sends a test email through the configured mailer, the way scheduling invitations are sent.');
+    }
+
+    protected function execute(InputInterface $input, OutputInterface $output): int
+    {
+        $io = new SymfonyStyle($input, $output);
+        $to = $input->getArgument('to');
+
+        if (!$this->inviteAddress) {
+            $io->error('INVITE_FROM_ADDRESS is not set, so Davis does not send scheduling invitations at all.');
+
+            return self::FAILURE;
+        }
+
+        $io->text(sprintf('Sending a test email from <info>%s</info> to <info>%s</info>…', $this->inviteAddress, $to));
+
+        try {
+            $this->mailer->send(
+                (new Email())
+                    ->from(new Address($this->inviteAddress, 'Davis'))
+                    ->to(new Address($to))
+                    ->subject('Davis test email')
+                    ->text("This is a test email from Davis.\n\nIf you received it, scheduling invitations can be delivered with the current configuration.\n")
+            );
+        } catch (RfcComplianceException $e) {
+            $io->error(sprintf('"%s" is not a valid email address: %s', $to, $e->getMessage()));
+
+            return self::FAILURE;
+        } catch (TransportExceptionInterface $e) {
+            $io->error('The email could not be sent: '.$e->getMessage());
+            $io->note('Check MAILER_DSN. Davis logs the same error and keeps saving events when this happens.');
+
+            return self::FAILURE;
+        }
+
+        $io->success('The email was handed to the transport. Check the destination mailbox.');
+
+        return self::SUCCESS;
+    }
+}
diff --git a/src/Controller/DAVController.php b/src/Controller/DAVController.php
index 6b67947e..02e2274e 100644
--- a/src/Controller/DAVController.php
+++ b/src/Controller/DAVController.php
@@ -276,7 +276,11 @@ private function initServer(string $authMethod, string $authRealm = User::DEFAUL
             $this->server->addPlugin(new \Sabre\CalDAV\ICSExportPlugin());
             $this->server->addPlugin(new \Sabre\CalDAV\Subscriptions\Plugin());
             if ($this->inviteAddress) {
-                $this->server->addPlugin(new DavisIMipPlugin($this->mailer, $this->inviteAddress, $this->publicDir));
+                $this->server->addPlugin(new DavisIMipPlugin($this->mailer, $this->inviteAddress, $this->publicDir, $this->logger));
+            } else {
+                // Without it the scheduling plugin above still answers, but no invitation ever
+                // leaves the server and nothing says so.
+                $this->logger->warning('CalDAV scheduling is enabled but INVITE_FROM_ADDRESS is not set: no invitation email will be sent.');
             }
         }
 
diff --git a/src/Form/UserType.php b/src/Form/UserType.php
index e43cbcb2..bbbd6e99 100644
--- a/src/Form/UserType.php
+++ b/src/Form/UserType.php
@@ -13,6 +13,7 @@
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\OptionsResolver\OptionsResolver;
+use Symfony\Component\Validator\Constraints as Assert;
 
 class UserType extends AbstractType
 {
@@ -27,10 +28,23 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
             ->add('displayName', TextType::class, [
                 'label' => 'form.displayName',
                 'mapped' => false,
+                'constraints' => [
+                    new Assert\Length(max: 255),
+                ],
             ])
+            // The field is unmapped — it belongs to the Principal, not the User — so the entity's
+            // own constraints never run on it and the rules have to live here. An empty address
+            // keeps the principal out of its own `calendar-user-address-set`, which means sabre
+            // never emits a scheduling message and invitations are silently never sent.
             ->add('email', EmailType::class, [
                 'label' => 'form.email',
                 'mapped' => false,
+                'help' => 'form.email.help',
+                'constraints' => [
+                    new Assert\NotBlank(),
+                    new Assert\Email(),
+                    new Assert\Length(max: 255),
+                ],
             ])
             ->add('password', RepeatedType::class, [
                 'type' => PasswordType::class,
diff --git a/src/Plugins/DavisIMipPlugin.php b/src/Plugins/DavisIMipPlugin.php
index bd0cf8b9..0b0be0ee 100644
--- a/src/Plugins/DavisIMipPlugin.php
+++ b/src/Plugins/DavisIMipPlugin.php
@@ -5,12 +5,15 @@
 use DantSu\OpenStreetMapStaticAPI\LatLng;
 use DantSu\OpenStreetMapStaticAPI\Markers;
 use DantSu\OpenStreetMapStaticAPI\OpenStreetMap;
+use Psr\Log\LoggerInterface;
 use Sabre\CalDAV\Schedule\IMipPlugin as SabreBaseIMipPlugin;
 use Sabre\DAV;
 use Sabre\VObject\ITip;
 use Symfony\Bridge\Twig\Mime\TemplatedEmail;
+use Symfony\Component\Mailer\Exception\TransportExceptionInterface;
 use Symfony\Component\Mailer\MailerInterface;
 use Symfony\Component\Mime\Address;
+use Symfony\Component\Mime\Exception\RfcComplianceException;
 
 /**
  * iMIP handler.
@@ -34,14 +37,20 @@ final class DavisIMipPlugin extends SabreBaseIMipPlugin
      */
     protected $publicDir;
 
+    /**
+     * @var LoggerInterface
+     */
+    private $logger;
+
     /**
      * Creates the email handler.
      */
-    public function __construct(MailerInterface $mailer, string $senderEmail, string $publicDir)
+    public function __construct(MailerInterface $mailer, string $senderEmail, string $publicDir, LoggerInterface $logger)
     {
         $this->mailer = $mailer;
         $this->senderEmail = $senderEmail;
         $this->publicDir = $publicDir;
+        $this->logger = $logger;
     }
 
     /**
@@ -52,6 +61,8 @@ public function schedule(ITip\Message $itip)
         // Not sending any emails if the system considers the update
         // insignificant.
         if (!$itip->significantChange) {
+            $this->logger->debug('iMIP: no email for an insignificant change', ['method' => $itip->method, 'recipient' => $itip->recipient]);
+
             if (empty($itip->scheduleStatus)) {
                 $itip->scheduleStatus = '1.0;We got the message, but it\'s not significant enough to warrant an email';
             }
@@ -63,6 +74,9 @@ public function schedule(ITip\Message $itip)
 
         if ('mailto' !== parse_url($itip->sender, PHP_URL_SCHEME)
             || 'mailto' !== parse_url($itip->recipient, PHP_URL_SCHEME)) {
+            // iTIP allows other schemes; this plugin only knows how to send email.
+            $this->logger->warning('iMIP: not an email exchange, no invitation sent', ['sender' => $itip->sender, 'recipient' => $itip->recipient]);
+
             return;
         }
 
@@ -90,6 +104,9 @@ public function schedule(ITip\Message $itip)
         }
 
         $subject = 'CalDAV message';
+        // Anything other than the three methods below leaves the template without an action to
+        // render, so the message is not one this plugin knows how to word.
+        $action = null;
         switch (strtoupper($itip->method)) {
             case 'REPLY':
                 // In the case of a reply, we need to find the `PARTSTAT` from
@@ -109,6 +126,7 @@ public function schedule(ITip\Message $itip)
                         $action = 'TENTATIVE';
                         break;
                     default:
+                        $this->logger->warning('iMIP: unsupported PARTSTAT in a REPLY, no email sent', ['partstat' => $partstat, 'recipient' => $itip->recipient]);
                         $itip->scheduleStatus = '5.0;Email not delivered. We didn\'t understand this PARTSTAT.';
 
                         return;
@@ -123,6 +141,11 @@ public function schedule(ITip\Message $itip)
                 $subject = '"'.$summary.'" has been canceled.';
                 $action = 'CANCEL';
                 break;
+            default:
+                $this->logger->warning('iMIP: unsupported iTIP method, no email sent', ['method' => $itip->method, 'recipient' => $itip->recipient]);
+                $itip->scheduleStatus = '5.0;Email not delivered. We don\'t know how to send this iTIP method.';
+
+                return;
         }
 
         // Construct objects for the mail template
@@ -192,14 +215,21 @@ public function schedule(ITip\Message $itip)
                 $latLng = new LatLng($coordinates['latitude'], $coordinates['longitude']);
 
                 // https://github.com/DantSu/php-osm-static-api
-                $locationImageDataAsBase64 = (new OpenStreetMap($latLng, $zoom, $width, $height))
-                    ->addMarkers(
-                        (new Markers($this->publicDir.'/images/marker.png'))
-                            ->setAnchor(Markers::ANCHOR_CENTER, Markers::ANCHOR_BOTTOM)
-                            ->addMarker(new LatLng($coordinates['latitude'], $coordinates['longitude']))
-                    )
-                    ->getImage()
-                    ->getBase64PNG();
+                // This fetches map tiles over the network. The map is decoration on an invitation,
+                // so a tile server that is unreachable or slow must not take the invitation — and
+                // with it the client's PUT — down with it.
+                try {
+                    $locationImageDataAsBase64 = (new OpenStreetMap($latLng, $zoom, $width, $height))
+                        ->addMarkers(
+                            (new Markers($this->publicDir.'/images/marker.png'))
+                                ->setAnchor(Markers::ANCHOR_CENTER, Markers::ANCHOR_BOTTOM)
+                                ->addMarker(new LatLng($coordinates['latitude'], $coordinates['longitude']))
+                        )
+                        ->getImage()
+                        ->getBase64PNG();
+                } catch (\Throwable $e) {
+                    $this->logger->warning('iMIP: the location map could not be rendered, sending the invitation without it', ['exception' => $e->getMessage()]);
+                }
 
                 $locationLink =
                     'https://www.openstreetmap.org'.
@@ -224,11 +254,24 @@ public function schedule(ITip\Message $itip)
             $mailSenderName = $senderEmail.' '.static::MESSAGE_ORIGIN_INDICATOR;
         }
 
-        $message = (new TemplatedEmail())
-            ->from(new Address($this->senderEmail, $mailSenderName))
-            ->to(new Address($recipientEmail, $recipientName ?? ''))
-            ->replyTo(new Address($senderEmail, $mailSenderName))
-            ->subject($subject);
+        try {
+            $message = (new TemplatedEmail())
+                ->from(new Address($this->senderEmail, $mailSenderName))
+                ->to(new Address($recipientEmail, $recipientName ?? ''))
+                ->replyTo(new Address($senderEmail, $mailSenderName))
+                ->subject($subject);
+        } catch (RfcComplianceException $e) {
+            // An attendee address comes from the organiser's client and is not validated anywhere
+            // before this point. Letting it through would abort the PUT that triggered it.
+            $this->logger->error('iMIP: an address in the invitation is not a valid email address, no email sent', [
+                'sender' => $senderEmail,
+                'recipient' => $recipientEmail,
+                'exception' => $e->getMessage(),
+            ]);
+            $itip->scheduleStatus = '5.3;Email not delivered. One of the addresses is not a valid email address.';
+
+            return;
+        }
 
         // Keep holiday auto-replies from bouncing back at invitations.
         $message->getHeaders()->addTextHeader('X-Auto-Response-Suppress', 'OOF, DR, RN, NRN, AutoReply');
@@ -259,7 +302,23 @@ public function schedule(ITip\Message $itip)
             $message->attach($itip->message->serialize(), 'invite.ics', 'text/calendar; method='.(string) $itip->method.'; charset=UTF-8');
         }
 
-        $this->mailer->send($message);
+        try {
+            $this->mailer->send($message);
+        } catch (TransportExceptionInterface $e) {
+            // The scheduling message is a side effect of storing the event: if the mail cannot be
+            // sent, the event still has to be saved. Throwing here would surface as a 500 on the
+            // client's PUT and lose it.
+            $this->logger->error('iMIP: the invitation could not be sent', [
+                'recipient' => $recipientEmail,
+                'method' => $itip->method,
+                'exception' => $e->getMessage(),
+            ]);
+            $itip->scheduleStatus = '5.1;Email not delivered. The mail transport is unavailable.';
+
+            return;
+        }
+
+        $this->logger->info('iMIP: invitation sent', ['recipient' => $recipientEmail, 'method' => $itip->method]);
 
         if (false === $deliveredLocally) {
             $itip->scheduleStatus = '1.1;Scheduling message is sent via iMip.';
diff --git a/tests/Functional/Controllers/UserControllerTest.php b/tests/Functional/Controllers/UserControllerTest.php
index 45cb28e2..903beff8 100644
--- a/tests/Functional/Controllers/UserControllerTest.php
+++ b/tests/Functional/Controllers/UserControllerTest.php
@@ -91,6 +91,36 @@ public function testUserNew(): void
         $this->assertAnySelectorTextContains('h5', 'New test User');
     }
 
+    /**
+     * The address is what sabre puts in the principal's `calendar-user-address-set`, and it only
+     * emits a scheduling message when the event's organiser matches one of those. An account saved
+     * without an address therefore never sends an invitation, and nothing says so at the time.
+     */
+    public function testUserCreationRequiresAnEmailAddress(): void
+    {
+        $client = static::createClient();
+        $client->loginUser(new AdminUser('admin', 'test'));
+
+        foreach (['', 'not-an-address'] as $email) {
+            $crawler = $client->request('GET', '/users/new');
+            $form = $crawler->selectButton('user_save')->form();
+
+            $client->submit($form, [
+                'user[username]' => 'no_email_user',
+                'user[displayName]' => 'No email',
+                'user[email]' => $email,
+                'user[password][first]' => 'coucou',
+                'user[password][second]' => 'coucou',
+            ]);
+
+            $this->assertResponseIsSuccessful(sprintf('"%s" should be refused by the form', $email));
+            $this->assertSelectorExists('.invalid-feedback, .form-error-message');
+        }
+
+        $em = static::getContainer()->get('doctrine.orm.entity_manager');
+        $this->assertNull($em->getRepository(User::class)->findOneBy(['username' => 'no_email_user']));
+    }
+
     public function testUserDelete(): void
     {
         $user = new AdminUser('admin', 'test');
diff --git a/tests/Functional/Plugins/ImipPluginTest.php b/tests/Functional/Plugins/ImipPluginTest.php
new file mode 100644
index 00000000..5811ec20
--- /dev/null
+++ b/tests/Functional/Plugins/ImipPluginTest.php
@@ -0,0 +1,146 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Functional\Plugins;
+
+use App\Plugins\DavisIMipPlugin;
+use Psr\Log\AbstractLogger;
+use Sabre\VObject\ITip;
+use Sabre\VObject\Reader;
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+use Symfony\Component\Mailer\Envelope;
+use Symfony\Component\Mailer\Exception\TransportException;
+use Symfony\Component\Mailer\MailerInterface;
+use Symfony\Component\Mime\RawMessage;
+
+/**
+ * Scheduling runs inside the PUT that stores the event. Anything thrown here reaches sabre and
+ * comes back to the client as a 500, with the event never written — so the plugin has to handle
+ * its own failures and record why.
+ */
+class ImipPluginTest extends KernelTestCase
+{
+    private const EVENT = "BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:-//Davis//Test//EN\r\nBEGIN:VEVENT\r\nUID:imip-1\r\nDTSTAMP:20260101T100000Z\r\nDTSTART:20261201T100000Z\r\nDTEND:20261201T110000Z\r\nSUMMARY:Test meeting\r\nORGANIZER;CN=Organiser:mailto:organiser@example.org\r\nATTENDEE;CN=Attendee;PARTSTAT=NEEDS-ACTION:mailto:attendee@example.org\r\nEND:VEVENT\r\nEND:VCALENDAR\r\n";
+
+    private function message(string $recipient = 'mailto:attendee@example.org'): ITip\Message
+    {
+        $message = new ITip\Message();
+        $message->method = 'REQUEST';
+        $message->sequence = 1;
+        $message->sender = 'mailto:organiser@example.org';
+        $message->senderName = 'Organiser';
+        $message->recipient = $recipient;
+        $message->recipientName = 'Attendee';
+        $message->significantChange = true;
+        $message->message = Reader::read(self::EVENT);
+
+        return $message;
+    }
+
+    private function plugin(MailerInterface $mailer, array &$logs): DavisIMipPlugin
+    {
+        self::bootKernel();
+
+        $logger = new class($logs) extends AbstractLogger {
+            public function __construct(private array &$logs)
+            {
+            }
+
+            public function log($level, $message, array $context = []): void
+            {
+                $this->logs[] = $level.': '.$message;
+            }
+        };
+
+        return new DavisIMipPlugin(
+            $mailer,
+            'no-reply@example.org',
+            static::getContainer()->getParameter('kernel.project_dir').'/public',
+            $logger
+        );
+    }
+
+    private function mailer(?\Throwable $failure): MailerInterface
+    {
+        return new class($failure) implements MailerInterface {
+            public array $sent = [];
+
+            public function __construct(private ?\Throwable $failure)
+            {
+            }
+
+            public function send(RawMessage $message, ?Envelope $envelope = null): void
+            {
+                if ($this->failure) {
+                    throw $this->failure;
+                }
+
+                $this->sent[] = $message;
+            }
+        };
+    }
+
+    public function testAnUnreachableTransportDoesNotAbortTheSchedulingEvent(): void
+    {
+        $logs = [];
+        $plugin = $this->plugin($this->mailer(new TransportException('Connection refused')), $logs);
+
+        $message = $this->message();
+        $plugin->schedule($message);
+
+        $this->assertStringStartsWith('5.1', (string) $message->scheduleStatus);
+        $this->assertContains('error: iMIP: the invitation could not be sent', $logs);
+    }
+
+    public function testAnAddressThatIsNotAnEmailAddressDoesNotAbortTheSchedulingEvent(): void
+    {
+        $logs = [];
+        $plugin = $this->plugin($this->mailer(null), $logs);
+
+        $message = $this->message('mailto:attendee(at)example.org');
+        $plugin->schedule($message);
+
+        $this->assertStringStartsWith('5.3', (string) $message->scheduleStatus);
+        $this->assertContains('error: iMIP: an address in the invitation is not a valid email address, no email sent', $logs);
+    }
+
+    public function testAnUnsupportedItipMethodIsReportedInsteadOfRenderingWithoutAnAction(): void
+    {
+        $logs = [];
+        $plugin = $this->plugin($mailer = $this->mailer(null), $logs);
+
+        $message = $this->message();
+        $message->method = 'COUNTER';
+        $plugin->schedule($message);
+
+        $this->assertStringStartsWith('5.0', (string) $message->scheduleStatus);
+        $this->assertContains('warning: iMIP: unsupported iTIP method, no email sent', $logs);
+        $this->assertSame([], $mailer->sent);
+    }
+
+    public function testANonMailtoRecipientIsLogged(): void
+    {
+        $logs = [];
+        $plugin = $this->plugin($mailer = $this->mailer(null), $logs);
+
+        $message = $this->message('https://example.org/attendee');
+        $plugin->schedule($message);
+
+        $this->assertContains('warning: iMIP: not an email exchange, no invitation sent', $logs);
+        $this->assertSame([], $mailer->sent);
+    }
+
+    public function testASuccessfulSendIsLoggedAndReported(): void
+    {
+        $logs = [];
+        $plugin = $this->plugin($mailer = $this->mailer(null), $logs);
+
+        $message = $this->message();
+        $plugin->schedule($message);
+
+        $this->assertStringStartsWith('1.1', (string) $message->scheduleStatus);
+        $this->assertContains('info: iMIP: invitation sent', $logs);
+        $this->assertCount(1, $mailer->sent);
+    }
+}
diff --git a/translations/messages+intl-icu.de.xlf b/translations/messages+intl-icu.de.xlf
index 3f9a28c7..df5afb96 100644
--- a/translations/messages+intl-icu.de.xlf
+++ b/translations/messages+intl-icu.de.xlf
@@ -325,6 +325,10 @@
         <source>form.email</source>
         <target>E-Mail</target>
       </trans-unit>
+      <trans-unit id="frmEmlHlp" resname="form.email.help">
+        <source>form.email.help</source>
+        <target>Wird als Kalenderadresse für Einladungen verwendet: Sie muss mit der Adresse übereinstimmen, die der Client als Organisator sendet, sonst werden keine Einladungen versendet.</target>
+      </trans-unit>
       <trans-unit id="RQWeqAY" resname="form.admin">
         <source>form.admin</source>
         <target>Ist dieser Benutzer ein Administrator?</target>
diff --git a/translations/messages+intl-icu.en.xlf b/translations/messages+intl-icu.en.xlf
index 4c6e1cd4..1b8fcb28 100644
--- a/translations/messages+intl-icu.en.xlf
+++ b/translations/messages+intl-icu.en.xlf
@@ -325,6 +325,10 @@
         <source>form.email</source>
         <target>Email</target>
       </trans-unit>
+      <trans-unit id="frmEmlHlp" resname="form.email.help">
+        <source>form.email.help</source>
+        <target>Used as the calendar address for scheduling: it has to match the address the user’s client sends as the organiser, or invitations are never sent.</target>
+      </trans-unit>
       <trans-unit id="RQWeqAY" resname="form.admin">
         <source>form.admin</source>
         <target>Is this user an administrator ?</target>
diff --git a/translations/messages+intl-icu.fr.xliff b/translations/messages+intl-icu.fr.xliff
index fad1aede..24271d7c 100644
--- a/translations/messages+intl-icu.fr.xliff
+++ b/translations/messages+intl-icu.fr.xliff
@@ -325,6 +325,10 @@
         <source>form.email</source>
         <target>Email</target>
       </trans-unit>
+      <trans-unit id="frmEmlHlp" resname="form.email.help">
+        <source>form.email.help</source>
+        <target>Sert d'adresse de calendrier pour les invitations : elle doit correspondre à celle que le client envoie comme organisateur, sinon aucune invitation n'est envoyée.</target>
+      </trans-unit>
       <trans-unit id="RQWeqAY" resname="form.admin">
         <source>form.admin</source>
         <target>Cet utilisateur est-il administrateur ?</target>