Most of our servers have a 60 checks per hour limit. If you hit this limit in any hour you'll be locked out for the rest of the hour. you will need to click > tools > options > general > and disable where it says "check for new messages every xx minutes" If you do not want to disable it just set it to check less often. Keep in mind, the more computers you have auto checking or checking the mail, the quicker you will hit this limit.
If you are having trouble sending email, check that your SMTP (Outgoing mail) port is set to 465. Here's how:
Microsoft Outlook 2002/2003:
1. From the "Tools" menu, select "E-mail Accounts"
2. Choose "View or Change existing email accounts" and click on "Next"
3. Choose your email (POP) account and click on the "Change" button
4. Click on "More Settings"
5. Click on the "Advanced" tab
6. Next to "Outgoing server (SMTP)", change port 25 to 465
7. Click "OK", then click "Next" and "Finish"
Microsoft Outlook 2007:
1. From the "Tools" menu, select "Account Settings"
2. Choose the "Email" tab and double click on your email (POP) account
3. Click on the "More Settings" button
4. Click on the "Advanced" tab
5. Next to "Outgoing server (SMTP)", change port 25 to 465
Microsoft Outlook 98/2000, Outlook Express:
1. From the "Tools" menu, select "Accounts"
2. Select your email (POP) account and click on the "Properties" button
3. Click on the "Advanced" tab
4. Next to "Outgoing server (SMTP), change port 25 to 465
5. Click "Apply", then click "OK" and "Close"
Thunderbird:
1. From the "Tools" menu select "Account Settings"
2. A box will open. Select "Outgoing server SMTP"
3. In the box update your server name to mail.yourdomainname.com and change the port to 465.
4. Select "Ok".