The Mac Admin's Blog

In the scenario where you are able to receive mails but unable to send it because the Send button is grayed out or is completely inactive. Try those steps out, this has worked many of my home users. Launch Mail. Go to the Mail menu & choose Preferences . Click on Accounts in the Preferences window.  Open the Account Information pane. Here could be the first reason, that the "Outgoing Mail Server (SMTP)" pop-up menu could be set to "None". Change it and select your server from the "Outgoing Mail Server (SMTP)" pop-up menu. These steps should work, so run a test & see if you are able to send the mails. If this did not work then the problem should be in the settings of your SMTP server. Go to the Mail menu & choose Preferences once again.  Click on Accounts in the Preferences window & select your account from the left side. Click the Account Information pane. Here in the "Outgoing Mail Server (SMTP)" pop-up