These instructions assume you already have an email account setup in Entourage.
All SingleEdge mail servers require SMTP authentication before mail is allowed to relay (from external networks) through them. If you are having problems sending outbound email using Microsoft Entourage and receive an email bounce with an error like this:
Remote host said: 553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)
Then either your Microsoft Entourage mail client is configured incorrectly or your servers (here at SingleEdge) have not been setup by SingleEdge Superior Support to allow mail relaying through either of our SMTP servers. Follow these steps to successfully relay mail through either of our servers externally.
1. Open Microsoft Entourage
2. Goto TOOLS --> Accounts

3. Highlight your account and click edit.

6. Verify that all of your email account settings are correct:
a. Account Name = A unique name to identify this account to Entourage. Your e-mail address is a good choice
b. Name = Your Name. This will show up in the "From" field of any messages you send.
c. E-mail address: = Your e-mail address. This will show up in the "From" and "Reply-to" fields of any messages you send.
d. Account ID: = Your e-mail address. This is used as your username for logon to the server.
e. POP server: = mail.yourdomain.tld (EXAMPLE: mail2.singleedge.com).
f. Password: = Your e-mail password. This should have been given to you by your administrator.
g. SMTP server = mail.yourdomain.tld (Example: mail2.singleedge.com)
7. Now click the "Click here for advanced sending options" button.

8. Place a check in the box labled "SMTP server requires authentication".
9. Make sure the radio button labled "Use same settings as receiving mail server" is selected.

10. Close the advanced sending options window and click OK.
After making these changes, try and send a test email out. If you are still having problems, try restarting your Entourage or even your computer before asking for support.
Thanks
SingleEdge Support Team
support@singleedge.com
801-265-1035 x 1