Hi Everyone, I really am stumped at this point. Anyone who could offer any advice, please please do!!

As of 3am on Friday, users can no longer receive email constantly on their portable devices. Users were able to add their office 365 account to their portable devices before this time using Active Sync, but now users who have the accounts set up prior to this time receive an error - cannot connect to server, even though on their phone settings the device shows as ok, but with a successful sync time of Friday. If you start logging, the retrieval shows an error.

Users who try and add their account since this time simply are unable to verify account information. The IMAP Server setting is correct - the same as showing in their mailbox settings, and for users who couldn't autodiscover previously, this setting worked - until now.

On testexchangeconnectivity.com, my admin account passes the activesync fine, with no errors. A standard user now receives an error:

The IMAP service is being tested.
There was an error testing the IMAP service

Additional Details
Secured: CN=outlook.com, OU=Exchange, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
S: * OK The Microsoft Exchange IMAP4 service is ready. [SABLAE4AUABSAEQAMAAyADEAMQBDAEEAMAAwADMALgBhAHAAYw BwAHIAZAAwADIALgBwAHIAbwBkAC4AbwB1AHQAbABvAG8AawAu AGMAbwBtAA==]
C: 1 CAPABILITY
S: * CAPABILITY IMAP4 IMAP4rev1 AUTH=PLAIN UIDPLUS CHILDREN IDLE NAMESPACE LITERAL+
1 OK CAPABILITY completed.
C: 2 LOGIN ########@mydomain.org <password>
S: 2 NO LOGIN failed.
C: 3 LIST "" *
S: 3 BAD Command received in Invalid state.
Microsoft.Exchange.Tools.ExRca.Tests.ImapPop.MailP rotocolException: 3 BAD Command received in Invalid state.
at Microsoft.Exchange.Tools.ExRca.Tests.ImapPop.ImapP rotocolTester.SendCommand(String command, String logString)
at Microsoft.Exchange.Tools.ExRca.Tests.ImapPop.BaseP rotocolTest.PerformTestReally()


The successful test from my account is below - the only difference being that I use @mydomain.onmicrosoft.com rather than @mydomain.org
Successfully tested the IMAP4 service
Secured: CN=outlook.com, OU=Exchange, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
S: * OK The Microsoft Exchange IMAP4 service is ready. [SABLAFgAUABSAEQAMAAyADEAMABDAEEAMAAwADEALgBhAHAAYw BwAHIAZAAwADIALgBwAHIAbwBkAC4AbwB1AHQAbABvAG8AawAu AGMAbwBtAA==]
C: 1 CAPABILITY
S: * CAPABILITY IMAP4 IMAP4rev1 AUTH=PLAIN UIDPLUS CHILDREN IDLE NAMESPACE LITERAL+
1 OK CAPABILITY completed.
C: 2 LOGIN myadmin@mydomain.onmicrosoft.com <password>
S: 2 OK LOGIN completed.
C: 3 LIST "" *
S: * LIST (\HasNoChildren) "/" Calendar
* LIST (\HasNoChildren) "/" Contacts
* LIST (\HasNoChildren) "/" "Deleted Items"
* LIST (\HasNoChildren) "/" Drafts
* LIST (\Marked \HasNoChildren) "/" INBOX
* LIST (\HasNoChildren) "/" Journal
* LIST (\HasNoChildren) "/" "Junk E-Mail"
* LIST (\HasNoChildren) "/" Notes
* LIST (\HasNoChildren) "/" Outbox
* LIST (\HasNoChildren) "/" "Sent Items"
* LIST (\HasNoChildren) "/" Tasks
3 OK LIST completed.
C: 4 LOGOUT
S: * BYE Microsoft Exchange Server 2010 IMAP4 server signing off.
4 OK LOGOUT completed.

If anyone has any advice on this is would be greatly appreciated.

Many Thanks in advance...