What is the domain name and what 365 Plan do you have?

optixdigital.ae, and we're on P1 Plan.

Thank you!

Looking at DNS records you autodiscover seems to be fully propagated worldwide.  Have you changed the usernames to your domain?

On the Portal click on users on the left

Under the username column are they all like user@optixdigital.ae or like user@optixdigital.onmicrosoft.com?

Yes, all the user names are user@optixdigital.ae.

Thanks Richard for looking into this.

OK, do you have any spare licenses?  Is it posible to set up a user account for me (non-administrator) so that I can run a connection test here in the UK.  If so email the username and password to richard@dcssouthwest.com

For the Apple devices, have you tried adding the accounts with the email address as .onmicrosoft but the username as optixdigital.ae.

If you are getting invalid username that suggests that it is not autodiscover, as the client device is finding the account but not authenticting.

also what format are you using as the username, sometimes people get this wrong?  It should be in the format of username@optixdigital.ae and not username

Yes, I can confirm that the username is in the format user@domain.com. We're transiting from Google Apps, and we're already use to this.

What results do you get from running test from here;

www.testexchangeconnectivity.com

I am assuming you did not use the 365 tab at the top of the test, should have pointed that one out

I did, this is the Office365  / Outlook Anywhere (RPC over HTTP)

Should I run any other test?

I'm pasting again the result:

	Testing RPC/HTTP connectivity.
	The RPC/HTTP test failed.
	Test Steps   ExRCA is attempting to test Autodiscover for user@optixdigital.ae.   Testing Autodiscover failed.   Test Steps   Attempting each method of contacting the Autodiscover service.   The Autodiscover service couldn't be contacted successfully by any method.   Test Steps   Attempting to test potential Autodiscover URL https://optixdigital.ae/AutoDiscover/AutoDiscover.xml   Testing of this potential Autodiscover URL failed.   Test Steps   Attempting to resolve the host name optixdigital.ae in DNS.   The host name resolved successfully.   Additional Details   IP addresses returned: 87.106.38.121 Testing TCP port 443 on host optixdigital.ae to ensure it's listening and open.   The port was opened successfully. Testing the SSL certificate to make sure it's valid.   The SSL certificate failed one or more certificate validation checks.   Test Steps   ExRCA is attempting to obtain the SSL certificate from remote server optixdigital.ae on port 443.   ExRCA successfully obtained the remote SSL certificate.   Additional Details   Remote Certificate Subject: E=info@plesk.com, CN=plesk, OU=Plesk, O="SWsoft, Inc.", L=Herndon, S=Virginia, C=US, Issuer: E=info@plesk.com, CN=plesk, OU=Plesk, O="SWsoft, Inc.", L=Herndon, S=Virginia, C=US. Validating the certificate name.   Certificate name validation failed.    Tell me more about this issue and how to resolve it   Additional Details   Host name optixdigital.ae doesn't match any name found on the server certificate E=info@plesk.com, CN=plesk, OU=Plesk, O="SWsoft, Inc.", L=Herndon, S=Virginia, C=US. Attempting to test potential Autodiscover URL https://autodiscover.optixdigital.ae/AutoDiscover/AutoDiscover.xml   Testing of this potential Autodiscover URL failed.   Test Steps   Attempting to resolve the host name autodiscover.optixdigital.ae in DNS.   The host name resolved successfully.   Additional Details   IP addresses returned: 157.56.240.137 Testing TCP port 443 on host autodiscover.optixdigital.ae to ensure it's listening and open.   The specified port is either blocked, not listening, or not producing the expected response.    Tell me more about this issue and how to resolve it   Additional Details   A network error occurred while communicating with the remote host. Attempting to contact the Autodiscover service using the HTTP redirect method.   The attempt to contact Autodiscover using the HTTP Redirect method failed.   Test Steps   Attempting to resolve the host name autodiscover.optixdigital.ae in DNS.   The host name resolved successfully.   Additional Details   IP addresses returned: 157.56.240.137 Testing TCP port 80 on host autodiscover.optixdigital.ae to ensure it's listening and open.   The port was opened successfully. ExRCA is checking the host autodiscover.optixdigital.ae for an HTTP redirect to the Autodiscover service.   The redirect (HTTP 301/302) response was received successfully.   Additional Details   Redirect URL: https://autodiscover-s.outlook.com/Autodiscover/Autodiscover.xml Attempting to test potential Autodiscover URL https://autodiscover-s.outlook.com/Autodiscover/Autodiscover.xml   Testing of this potential Autodiscover URL failed.   Test Steps   Attempting to resolve the host name autodiscover-s.outlook.com in DNS.   The host name resolved successfully.   Additional Details   IP addresses returned: 157.56.234.134, 157.56.240.86, 157.56.236.102, 157.56.244.230, 157.56.234.150, 157.56.240.102, 157.56.240.118, 157.56.240.134, 157.56.244.182, 157.56.244.214, 157.56.245.6, 157.56.236.86, 157.56.234.86, 157.56.236.118, 157.56.234.118, 157.56.236.134 Testing TCP port 443 on host autodiscover-s.outlook.com to ensure it's listening and open.   The port was opened successfully. Testing the SSL certificate to make sure it's valid.   The certificate passed all validation requirements.   Test Steps   ExRCA is attempting to obtain the SSL certificate from remote server autodiscover-s.outlook.com on port 443.   ExRCA successfully obtained the remote SSL certificate.   Additional Details   Remote Certificate Subject: CN=outlook.com, OU=Exchange, O=Microsoft Corporation, L=Redmond, S=Washington, C=US, Issuer: CN=Microsoft Secure Server Authority, DC=redmond, DC=corp, DC=microsoft, DC=com. Validating the certificate name.   The certificate name was validated successfully.   Additional Details   Host name autodiscover-s.outlook.com was found in the Certificate Subject Alternative Name entry. Certificate trust is being validated.   The certificate is trusted and all certificates are present in the chain.   Test Steps   ExRCA is attempting to build certificate chains for certificate CN=outlook.com, OU=Exchange, O=Microsoft Corporation, L=Redmond, S=Washington, C=US.   One or more certificate chains were constructed successfully.   Additional Details   A total of 1 chains were built. The highest quality chain ends in root certificate CN=GTE CyberTrust Global Root, OU="GTE CyberTrust Solutions, Inc.", O=GTE Corporation, C=US. Analyzing the certificate chains for compatibility problems with versions of Windows.   No Windows compatibility problems were identified.   Additional Details   The certificate chain has been validated up to a trusted root. Root = CN=GTE CyberTrust Global Root, OU="GTE CyberTrust Solutions, Inc.", O=GTE Corporation, C=US. Testing the certificate date to confirm the certificate is valid.   Date validation passed. The certificate hasn't expired.   Additional Details   The certificate is valid. NotBefore = 4/17/2012 9:26:21 PM, NotAfter = 4/17/2014 9:26:21 PM Checking the IIS configuration for client certificate authentication.   Client certificate authentication wasn't detected.   Additional Details   Accept/Require Client Certificates isn't configured. Attempting to send an Autodiscover POST request to potential Autodiscover URLs.   Autodiscover settings weren't obtained when the Autodiscover POST request was sent.   Test Steps   ExRCA is attempting to retrieve an XML Autodiscover response from URL https://autodiscover-s.outlook.com/Autodiscover/Autodiscover.xml for user user@optixdigital.ae.   The Autodiscover XML response was successfully retrieved.   Additional Details   An HTTPS redirect was received in response to the Autodiscover request. The redirect URL is https://pod51014.outlook.com/Autodiscover/Autodiscover.xml. Attempting to test potential Autodiscover URL https://pod51014.outlook.com/Autodiscover/Autodiscover.xml   Testing of this potential Autodiscover URL failed.   Test Steps   Attempting to resolve the host name pod51014.outlook.com in DNS.   The host name resolved successfully.   Additional Details   IP addresses returned: 157.56.252.22, 157.56.252.150, 157.56.248.38, 157.56.248.166 Testing TCP port 443 on host pod51014.outlook.com to ensure it's listening and open.   The port was opened successfully. Testing the SSL certificate to make sure it's valid.   The certificate passed all validation requirements.   Test Steps   ExRCA is attempting to obtain the SSL certificate from remote server pod51014.outlook.com on port 443.   ExRCA successfully obtained the remote SSL certificate.   Additional Details   Remote Certificate Subject: CN=outlook.com, OU=Exchange, O=Microsoft Corporation, L=Redmond, S=Washington, C=US, Issuer: CN=Microsoft Secure Server Authority, DC=redmond, DC=corp, DC=microsoft, DC=com. Validating the certificate name.   The certificate name was validated successfully.   Additional Details   Host name pod51014.outlook.com was found in the Certificate Subject Alternative Name entry. Certificate trust is being validated.   The certificate is trusted and all certificates are present in the chain.   Test Steps   ExRCA is attempting to build certificate chains for certificate CN=outlook.com, OU=Exchange, O=Microsoft Corporation, L=Redmond, S=Washington, C=US.   One or more certificate chains were constructed successfully.   Additional Details   A total of 1 chains were built. The highest quality chain ends in root certificate CN=GTE CyberTrust Global Root, OU="GTE CyberTrust Solutions, Inc.", O=GTE Corporation, C=US. Analyzing the certificate chains for compatibility problems with versions of Windows.   No Windows compatibility problems were identified.   Additional Details   The certificate chain has been validated up to a trusted root. Root = CN=GTE CyberTrust Global Root, OU="GTE CyberTrust Solutions, Inc.", O=GTE Corporation, C=US. Testing the certificate date to confirm the certificate is valid.   Date validation passed. The certificate hasn't expired.   Additional Details   The certificate is valid. NotBefore = 4/17/2012 9:26:21 PM, NotAfter = 4/17/2014 9:26:21 PM Checking the IIS configuration for client certificate authentication.   Client certificate authentication wasn't detected.   Additional Details   Accept/Require Client Certificates isn't configured. Attempting to send an Autodiscover POST request to potential Autodiscover URLs.   Autodiscover settings weren't obtained when the Autodiscover POST request was sent.   Test Steps   ExRCA is attempting to retrieve an XML Autodiscover response from URL https://pod51014.outlook.com/Autodiscover/Autodiscover.xml for user user@optixdigital.ae.   ExRCA failed to obtain an Autodiscover XML response.   Additional Details   An HTTP 401 Unauthorized response was received from the remote Unknown server. This is usually the result of an incorrect username or password. If you are attempting to log onto an Office 365 service, ensure you are using your full User Principal Name (UPN). Attempting to contact the Autodiscover service using the DNS SRV redirect method.   ExRCA failed to contact the Autodiscover service using the DNS SRV redirect method.   Test Steps   Attempting to locate SRV record _autodiscover._tcp.optixdigital.ae in DNS.   The Autodiscover SRV record wasn't found in DNS.    Tell me more about this issue and how to resolve it

'An HTTP 401 Unauthorized response was received from the remote Unknown' it means you may type wrong password or user name

I wish that was the case, unfortunately it is not.

This is a major bug, and I think it is related to the fact that some accounts on this domain were recreated after the originals were deleted.

I looks like it has something to do with permissions, and unfortunately the admin panel does not offer proper control over it.

A lot more than 72 hours have passed from the ns change.

You ns is correct.

but the error "An HTTP 401 Unauthorized response was received from the remote Unknown server. This is usually the result of an incorrect username or password. If you are attempting to log onto an Office 365 service, ensure you are using your full User Principal Name (UPN)."

You can reset the password and try it again.