I am experiencing this problem for the second day now. Whenever I try to send an email or somebody sends me an email on Outlook 2007, I can not send or receive it and an error occurs. At first I thought maybe the servers are down but it's the second day now and the same problem is happening. Is this an issue with my Outlook account? Can firewall be the reason for this? Will reinstalling Outlook fix the issue?
Error occurs while sending or receiving email on Outlook 2007.
There can be many reasons of error while sending/receiving mail. Try out some of the solutions listed below.
1.  It might happen that your outlook profile is corrupt.
Follow these instructions to solve this error.
a.  Go to windows control panel.
b.  Click on Mail.
c.  Go to mail setup.
d.  Click on show profiles.
e.  Add / Create new outlook profile, Add your email account to it.
Try sending the message again.
2.  Your SMTP settings might be wrong.
Try re configuring SMTP settings again. It might happen that outlook is not configured with correct SMTP settings.Â