Outlook 2010 - Sending emails to same domain accounts fails

Outlook 2010 - Sending emails to same domain accounts fails

Hello,

I configured my email account in outlook 2010 following the instructions in this page:

    https://zohomail.wiki.zoho.com/Configuring-as-POP-Account.html

I can receive emails properly but I have an issue with sending them. It works great when I send an email out to an external account (I mean hotmail, gmail, etc.) but for some reason I'm not able to send emails to accounts with the same domain as I, which in fact are all zoho accounts (with my own domain).

When I press the 'send' button, there's no error, but the other account never receives the email. After 10 tries, my account was blocked to send emails, so it seems that the emails that I was trying to send got bounced, however I never received the bounce notification.

It is weird that everything works properly from the webmail account, so I thought it could be a configuration issue, but I followed the instructions a lot of times and it doesn't look like I miss anything.

I also tried the IMAP configuration and I have the same issue.

I configured an account in my phone with W7 mobile and it happens there as well.

Any thoughts?

Thanks