IO-1937 Update email sizing error message.

client/src/components/email-overlay/email-overlay.component.jsx

@@ -162,7 +162,10 @@ export function EmailOverlayComponent({
       <Tabs>
         {!bodyshop.uselocalmediaserver && (
           <Tabs.TabPane tab={t("emails.labels.documents")} key="documents">
-            <EmailDocumentsComponent selectedMediaState={selectedMediaState} />
+            <EmailDocumentsComponent
+              selectedMediaState={selectedMediaState}
+              form={form}
+            />
           </Tabs.TabPane>
         )}
         <Tabs.TabPane tab={t("emails.labels.attachments")} key="attachments">
@@ -188,7 +191,8 @@ export function EmailOverlayComponent({
                     0
                   );
 
-                  const limit = 9961472;
+                  const limit =
+                    10485760 - new Blob([form.getFieldValue("html")]).size;
 
                   if (totalSize > limit) {
                     return Promise.reject(t("general.errors.sizelimit"));