Why can I receive mail in Outlook but not send it?

Why can i not receive to or send from my outlook mail box?

• In an attempt to sync my Outlook Calendar with my Win 7 phone, I installed Outlook Connection on my PC. Now Outlook Inbox will no longer receive my email no allow me to send an email. In fact the send/receive button on the toolbar has dissappeared. I uninstalled Outlook Connection, hoping that would fix the problem. It didn't. What did I do wrong? How can I fix my Outlook?

• Answer:

  It is possible that you corrupted the .pst file when you sync the calendar with phone (yea MS office is a piece of crap!!!). The .pst file is like a database that store all email/contact/calendar info. You can find it in C:\Documents and Settings\Len\Local Settings\Application Data\Microsoft\Outlook\outlook.pst Try using a .pst repair program. I never delete my email so my .pst file slowly getting bigger and bigger. One day my outlook just stop working. I did some research and found that my .pst was bigger than the 4.5 GB limit (FFS it is 2012, they have the same problem since Office 97)