Icloud mail - not a valid Base-64 string

I can no longer send email from eMclient.

These are the SMPT settings which worked before and are correct per Apple.

Host smtp.mail.me.com
Port 587

Server requires authentication
use these credentials

Tried every SMTP setting - nothing works.
Tried changing ‘Signing and Encryption’ settings per another thread - no joy.

Tried different emails and the usual ‘hello world’ to myself - nothing.

I am using an apple one-time application password.

I can receive fine, I can send from my iPhone. But can’t send email from emClient.

Ran eMclient diagnostics which said there’s a problem, but the ‘fix’ option was not able to fix the problem.


log file follows…

2:11:17 PM [email protected] [SMTP] MailClient.Accounts.LoginException: The authentication failed due to the following reason:
"The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.
at MailClient.Protocols.Smtp.SmtpSendCommand.Authenticate(WorkerStatus status)
at MailClient.Protocols.Smtp.SmtpSendCommand.Connect(WorkerStatus status)
at MailClient.Protocols.Smtp.SmtpSendCommand.Execute(WorkerStatus status)
at MailClient.Commands.Command.Process(WorkerStatus status)
EnqueuedStackTrace =
at MailClient.Protocols.Smtp.SmtpAccount.<>c__DisplayClass3_0.b__0()
at MailClient.Protocols.Common.AccountBase.RunIfOnline(Action actionIfOnline, Action actionIfOffline)
at MailClient.Protocols.Smtp.SmtpAccount.SendAsync(IEnumerable1 items, Action1 sentItem, Action1 completed, CancellationToken cancellationToken) at MailClient.Accounts.BindingAccountBase.SendInternal() at MailClient.Accounts.BindingAccountBase.Send() at MailClient.Accounts.AccountManager.SendAllInternal() at MailClient.Accounts.AccountManager.SendAndReceiveAll() at MailClient.Program.<>c.<AfterStartup>b__208_0() at MailClient.Accounts.AccountManager.<>c__DisplayClass82_0.<InitializeOnlineMode>b__0(Object <p0>) at System.Threading.QueueUserWorkItemCallback.<>c.<.cctor>b__6_0(QueueUserWorkItemCallback quwi) at System.Threading.ExecutionContext.RunForThreadPoolUnsafe[TState](ExecutionContext executionContext, Action1 callback, TState& state)
at System.Threading.QueueUserWorkItemCallback.Execute()
at System.Threading.ThreadPoolWorkQueue.Dispatch()
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()