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We are receiving error Ox800CCC78 when we try to send an email. We are receiving emails just fine. When I try the repair tool in account settings, I receive error the server responded 550 5.1.0 The sender is rejected.. We are on Outlook 2013 and have never changed these settings. We noticed this approximately three months ago.
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It’s occurring with all e-mail address that we have set up in outlook that we are sending from.
We have four different e-mail addresses set up in Outlook (for four people), but all use the same incoming and same outgoing server names. Spectrum confirmed that those have not changed.
We are receiving emails. We just can’t send any. We get the Ox800CCC78 error.
So if I try to send an email from Outlook, it fails. Our Internet provider says it’s a Microsoft issue.
I contacted our provider and they say nothing has changed and it’s a Microsoft issue. They did a test.
So essentially the issue is happening with all email address that you’re sending to, as in not just one provider but all email providers?
Or all the email addresses that you’re using to send from?
Kind regards
Tim
It is happening with all email addresses. We have 4 addresses, but mainly use 2.
The outgoing server is smtp-server.wi.rr.com. The account type is POP3.
The outgoing port is 25.
The authentication for the outgoing server is set up to use the same authentication as the incoming mail server.
What I do not understand is why this just started. I am thinking our provider changed something?
Hi,
I'm Tim, an Independent Advisor here and a Microsoft user like you. I don't work for Microsoft and do not have access to any of your data on their system.
Error 0x800CCC78 usually indicates an issue with the outgoing server settings.
The 550 5.1.0 error suggests the server is rejecting the sender's address.
Double-check your outgoing server settings, including the authentication method and port numbers.
Also, verify that your sender email address is correct and not blocked.
Does the issue happen with all emails being sent?
Kind regards
Tim
