Imap problem in Office365, basic auth

Copper Contributor

Hi, I have problem with basic auth login to imap service. 

Cant login with basic auth to imap server. Connectivity analyzer error below.
User have acces to iamp/pop3/smtp, same with turn off modern auth. 

Please verify There was an error testing the IMAP service Collapse Additional Details Protocol Log: C: 1 CAPABILITY S: * OK The Microsoft Exchange IMAP4 service is ready. [RABCADMAUABSADAAOABDAEEAMAAwADEANwAuAGUAdQByAHAAcgBkADAAOAAuAHAAcgBvAGQALgBvAHUAdABsAG8AbwBrAC4AYwBvAG0A] S: * CAPABILITY IMAP4 IMAP4rev1 AUTH=PLAIN AUTH=XOAUTH2 SASL-IR UIDPLUS ID UNSELECT CHILDREN IDLE NAMESPACE LITERAL+ S: 1 OK CAPABILITY completed. C: 2 LOGIN ******** S: 2 NO LOGIN failed. Exception details: Message: The IMAP server responded with an error status "2 NO LOGIN failed.". Type: Microsoft.M365.RCA.Services.Protocols.Imap.ImapServerErrorException Stack trace: at Microsoft.M365.RCA.Services.Protocols.Imap.ImapCommand`1.CheckForOk(IList`1 response) at Microsoft.M365.RCA.Services.Protocols.Imap.LoginCommand.ProcessResponse(IList`1 response) at Microsoft.M365.RCA.Services.Protocols.ProtocolClient.[SendCommandAsync]d__17`1.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.M365.RCA.ConnectivityTests.ImapPop.BaseProtocolTest.[PerformTestInternalAsync]d__12.MoveNext()
3 Replies
Have you made sure that basic authentication is not turned off for your user/tenant? Also check whether the IMAP protocol itself is enabled.

@Vasil Michev 


Basic Authentication is on and IMAP is enabled for the user, but still getting this error

Hi @Sunildara ,


check is Microsoft maybe disabled basic authentication for your tenant, you might want to opt-out.

Login as administrator.




Click on Help. Type in and Diag: Enable Basic Auth in EXO Run.



Select your protocol.





You could have these issue for multiple reasons. This is just one of them. You can read about Opt out solution here - Basic Authentication and Exchange Online – September 2021 Update - Microsoft Tech Community