Add port 587 (used for STARTTLS) as an example SMTP port (#4893)

webapp/components/admin_console/email_settings.jsx

@@ -255,7 +255,7 @@ export default class EmailSettings extends AdminSettings {
                             defaultMessage='SMTP Server Port:'
                         />
                     }
-                    placeholder={Utils.localizeMessage('admin.email.smtpPortExample', 'Ex: "25", "465"')}
+                    placeholder={Utils.localizeMessage('admin.email.smtpPortExample', 'Ex: "25", "465", "587"')}
                     helpText={
                         <FormattedMessage
                             id='admin.email.smtpPortDescription'

webapp/i18n/en.json

@@ -281,7 +281,7 @@
   "admin.email.smtpPasswordExample": "Ex: \"yourpassword\", \"jcuS8PuvcpGhpgHhlcpT1Mx42pnqMxQY\"",
   "admin.email.smtpPasswordTitle": "SMTP Server Password:",
   "admin.email.smtpPortDescription": "Port of SMTP email server.",
-  "admin.email.smtpPortExample": "Ex: \"25\", \"465\"",
+  "admin.email.smtpPortExample": "Ex: \"25\", \"465\", \"587\"",
   "admin.email.smtpPortTitle": "SMTP Server Port:",
   "admin.email.smtpServerDescription": "Location of SMTP email server.",
   "admin.email.smtpServerExample": "Ex: \"smtp.yourcompany.com\", \"email-smtp.us-east-1.amazonaws.com\"",