Thanks, but the screen shots do not match what I see on my system. I followed the instructions but I don't have any outgoing SMTP server for my Exchange account. If I go to Mail/Preferences/Accounts and select the Exchange account, then in the Account Information tab click on 'Edit SMTP Server List...' under 'Outgoing Mail Server', I only see the SMTP server for my ISP mail account (not my Exchange account that I use at work):
If I go to Mail/Preferences/Accounts and select the Exchange account, and "Account Information", then both the "Internal Server" and the "Outgoing Mail Server" are correctly identified as being the Exchange server. But clicking on "Edit SMTP Server List" under the "Outgoing Mail Server" drop-down list, only shows me the SMTP server for my ISP.
This sounds correct to me, as I understand that Exchange does not use SMTP for outgoing mail if the connection to Exchange is via Exchange Web Services.