Solve SMTP Offline on Mac OS X Mail

Recent days, I have problems sending out email in Mail App, on Mac OS X Mountain Lion. Little invistigation shows that the accounts information for SMTP server are messed, wrong accounts are used for different servers. The solution is simple and straightforward:

  1. In Mail, open Preferences;
  2. In Accounts tap, select the account whose Outgoing Mail Server(SMTP) is labeled as offline;
  3. Click the SMTP server, and select Edit SMTP Server List from the list;
  4. Then you need to fill in the correct username and password.