If you are using Outlook Express (OE), Outlook, or Windows Mail, A HELO error ( 550 Access denied - Invalid HELO name (See RFC2821 4.1.1.1) ) can sometimes be generated by leaving the "My server requires authentication" checkbox unchecked. You may need to try checking off this checkbox.
Use the below examples to find this checkbox:
1. Outlook 2000
- Go to Tools > Services (or Tools > Accounts, if Services is not listed).
- Select your Internet E-Mail Account and press “Properties.”
- Go to the “Servers” tab, and check “My server requires authentication” under Outgoing Mail Server.
- Press “Settings,” select “Use same settings as my incoming mail server,” then
- press “OK” three times to save the changes & return to Outlook.
- Finally, restart your computer.
2. Outlook 2002 & 2003
- Go to Tools > E-Mail Accounts.
- Select “View or change existing e-mail accounts” and press “Next.”
- Select your Intermedia.NET POP/SMTP account and press “Change.”
- Press “More Settings.”
- Go to the “Outgoing Server” tab, and check “My outgoing server (SMTP) requires authentication.”
- Select “Use same settings as my incoming mail server” and press “OK.”
- Press “Next,” then press “Finish” to confirm your changes and return to Outlook.
- Finally, restart your computer.
3. Outlook Express
- Go to Tools > Accounts. Select the “Mail” tab.
- Select your Intermedia.NET account and press “Properties.”
- Go to the “Servers” tab, and check “My server requires authentication” under Outgoing Mail Server.
- Press “Settings,” select “Use same settings as my incoming mail server,” then
- press “OK” twice times to save the changes,
- then press “Close” to return to Outlook Express.
- Finally, restart your computer.
