The topic of this article is not supported by our customer support department, however for your convenience we are providing this material to assist you in troubleshooting potential issues related to this topic.

If you are receiving a 553 RCPT hosts Error Message when sending email via Outlook or another email client, you may want to ensure that you are set up to authenticate with your POP credentials before SMTP.  The mail server requires you, the user, to authenticate by logging into the incoming mail server before the server will allow you to send email.

To ensure this in Outlook 2007:

1. Click on “Tools” from the menu bar
2. Select “Account Settings”
3. Select your “Account” (double-click)
4. Click “More Settings”
5. Click the “Outgoing Server” tab
6. Check the “My Outgoing Server Requires Authentication” and check “Log on to incoming mail server before sending mail”
7. Save these settings

At times, Outlook will not follow the settings specified. If you are still receiving this error, then click the “Send/Receive” button and try to send again.