fix: Export messages additional emails not being validated (#34092)

Co-authored-by: gabriellsh <40830821+gabriellsh@users.noreply.github.com>

.changeset/selfish-fishes-move.md

@@ -0,0 +1,5 @@
+---
+"@rocket.chat/meteor": patch
+---
+
+fixes mail export form "To additional emails" field validation

apps/meteor/client/views/room/contextualBar/ExportMessages/MailExportForm.tsx

@@ -155,11 +155,8 @@ const MailExportForm = ({ formId, rid, onCancel, exportOptions }: MailExportForm
 									rules={{
 										validate: {
 											validateEmail: (additionalEmails) => {
-												if (additionalEmails === '') {
-													return undefined;
-												}
-
-												if (additionalEmails !== '' && validateEmail(additionalEmails)) {
+												const emails = additionalEmails?.split(',').map((email) => email.trim());
+												if (Array.isArray(emails) && emails.every((email) => validateEmail(email.trim()))) {
 													return undefined;
 												}