Outlook Not pulling Email

I just switched our companies Email accounts to DH and I have ran into a very odd problem. Some of the Outlook accounts (2002 to 2007) have no issue with connecting, receiving and sending email.

However other accounts I have setup are have severe issues. They refuse to pull email from DH’s servers. If I test the Outlook settings and I do not recieve error messages but the account is clearly not pulling email. I know this because I send test emails via working outlook accounts and gmail. If I webmail to these accounts which will not pull email they have the test emails in squirrel.

Does anyone have any idea how to fix this?

Well after spending most of the day with this and some other migration issues. DH’s Tech staff came through. I completely forgot that each computer locally caches DNS information. If anyone else is trying to do this and has issues make sure to go to cmd and use ipconfig /flushdns. After you do this, you should not be having anymore problems.