Can someone clear up my confusion about how SSIS Send Mail Task works? I created a simple ssis package on my home laptop that only had a Send Mail task, to play around with to see how that task works to send email. I had iis installed, and used it when configuring the smtp connection. In the editor, I entered 127.0.0.1 as SMTP server.Everything worked, and life was good. Only thing I should mention, when I first did this I had no email account (e.g. Outlook express, Outlook, etc.) set up on my laptop. (As I think about it more though, I think it MAY only have worked if Outlook or Outlook express were open, not sure...) Later, I decided I wanted a desktop email program, and set up an account in Outlook 2010 to handle my aol emails. Some months after that, I returned to working with my email package, which now doesn't exactly seem to work anymore. When I execute it everything shows up green for successful send of email, but no email gets sent!. If Outlook isn't opened, the email winds up in the C:\inetpub\bad folder as junk. If Outlook is up, the email winds up in the "queue" folder as an Outlook msg, but never does go out. I THINK the reason no email is issued is because of a unique problem between AOl and Outlook (I get an error msg stating "Your IMAP server wants to alert you to the following: 1693 That mail is not currently available.") I think after much poking around online I have a solution to the problem posed by the message. But it suggests to me that Outlook is now trying to send my Send Mail task messages, and not iis. So what I would like to know is this - if I specify 127.0.0.1 as name of the localhost, thinking that iis will handle sending of email, and I have any kind of mail client on my machine, which one is really in charge? I have only one Outlook account. (It does now say "IMAP/SMTP (send from this account by default)"). I made NO CHANGES to the Send Mail task or the package itself when I began using it again. I don't know much about email (if you haven't already guessed), and if someone could explain just what goes on in the (supposedly simple) Send Mail task when you use localhost/iis and have a email client on the machine I would really be learning a lot! Thanks in advance to whoever's got an answer.