Email notifications stop working

RUtt

This is the second time this has happened, but for some reason SQL Monitor is unable to send email notifications. I know the account is setup correctly because other apps on that same box can send mail through that account. When I send a test email it just says "Unable to send test email. Please check your settings". Last time this happened there was an update available so I installed the update and it started working again but I don't really want go through an uninstall/reinstall this time if I don't have to. I've tried removing and resetting up the mail settings and stopped/started the IIS service and it still won't send. I've been trying to identify if there is any errors being generated when this happens but haven't had any luck. This has been working fine for about a month and it just seemed to quit working today.