We are having an issue this morning where we can receive external emails but cannot send internal or external ones from Outlook or OWA. If I use:

Send-MailMessage –From <[email protected]> –To <[email protected]> –Subject “Test #01”-Body “Just a test message.” –SMTPServer <Server-Name> –Credential <domain\user>

the email is sent correctly which makes me think there is a connection issue with OWA and Outlook. However, outlook is reporting as Connected with exchange.

I have checked the message tracking in exchange tools and emails sent via outlook and OWA do not appear.

Nothing has changed on the server on the weekend so I don't really know where to start debugging this issue.

We are using Windows SBS 2011. We only have one send connector which isn't using Smart Hosts and is set to use DNS MX records. Use external DNS is not checked and I can ping google.com etc so doesn't appear to be a DNS issue (plus the email sends from the console anyway).

EDIT It appears that users using IMAP can send emails correctly, its only ones that rely on the normal exchange connection type that don't work.

EDIT Emails from IMAP are hitting the email queue's where as emails from the normal exchange accounts aren't.

EDIT It seems that some of the emails we tried to send yesterday sent at about 1am but now it won't work again..