I am running into a seemingly bizarre problem with Mail. My work uses Exchange. I have things setup on my iPhone 4S and iPad 2 with no issues; however, I am just not able to get things setup properly using Mail on 10.9 If I let it auto discover, it takes ages and eventually fails asking something about whether I have SSL properly enabled. If I enter in the info as seen on my iPad or iPhone, it then fails much more quickly with the message that "Trying to log in to this Exchange account failed. Verify that the username and password are correct." The password is definitely correct and the username appears so. I even typed the password elsewhere, for the weblogin screen, and cut and paste it in - still gives this message. Now on the iPad and iPhone it didn't have options for the port for SSL, you just toggle it on or off, so perhaps that is the issue here because it's asking for internal/external paths of EWS/Exchange.asmx I don't know enough about this to know if that makes any difference, I just know I have the same data in the same fields and it doesn't appear to work at all. I've even used the IP, as suggested on my work's IT site, and it makes no difference. My personal gmail account had no issues at all. The internal and external server are the same: mail.domain.ie username is set as what I login with. I've tried it as the both login and email@example.com neither does any good. I even tried it as domain\login and it gave the same error message. When I tried domain.ie\login it failed with a general error, so that wasn't correct Under advanced I have SSL in both categories ticked. The internal port in both is 443 and they are both listed as EWS/Exchange.asmx and ews/exchange.asmx accordingly. On my iPhone, it's set up as an Exchange and it the fields I have: server: mail.domain.ie domain: domain <-- no.ie on that one. Just the main bit. username: login password: password Use SSL is ticked on. Use Mime is ticked off. Any suggestions are appreciated.