eM Client will not send e-mails

I have recently changed my password for my Sky/Yahoo email account. Since then, coincidence or not? I have been unable to send mail from my eM Client account but can send using Sky/Yahoo account. When refreshing to send and receive all mail I receive new mail ok but outgoing mail remains in the Outbox and there is no error message to explain the reason why mail is not being sent.

eM Client is not an email provider, so it cannot be an eM Client account. Which email provider is it?

One thing you can try is to disable your anti-virus application and then try again.

Yahoo/Sky is the email provider. I can send and receive ok using this account. It is only the eM Client account which I use to receive all the mail and then save to respective folders that I am having issues with. I use Norton for Anti-Virus protection and have done so for many years but not had any issues in the past.

Did you disable your anti-virus application to test if it is the issue now?

Again, eM Client do not offer email services. Unless you are an employee of eM Client, and your email address ends in emclient.com, it is not an eM Client account. Who is the email provider? That means what is after the @ in the email address of the account that is not sending?

@sky.com

Go to Menu > Tools > Accounts, and click on the @sky.com account. Go to the SMTP tab and make sure that the port is 587 and the security policy is Force usage of SSL/TLS.

With your anti-virus application disabled, test to see if you can now send messages on the @sky.com email address.

If that works, then re-enable your anti-virus application and send another test message using the same email account.

I disabled Norton (anti virus) but it did not make any difference.

I have checked the port (587) and security policy is Force usage of SSL/TLS.
Still unable to send mail

Go to Menu > Tools Operations and look in the Error tab to see if there are any errors. Then go to the Log tab and scroll through till you find where the @sky.com SMTP is mentioned. See if there are any errors there.

Error Log for @sky.com SMTP
19:13:36 @sky.com [SMTP]  MailClient.Accounts.LoginException: The authentication failed due to the following reason:
19:13:36     "Unexpected end of stream.
19:13:36    at MailClient.Protocols.Smtp.SmtpSendCommand.Authenticate(WorkerStatus status)
19:13:36    at MailClient.Protocols.Smtp.SmtpSendCommand.Connect(WorkerStatus status)
19:13:36    at MailClient.Protocols.Smtp.SmtpSendCommand.Execute(WorkerStatus status)
19:13:36    at MailClient.Commands.Command.Process(WorkerStatus status)

Go to Menu > Tools > Accounts, and click on the @sky.com account. Go to the SMTP tab and change the port to  465  and the security policy to Use SSL/TLS on special port (legacy).

See if there is any difference.

No difference and still getting the same error log as above

If the account is IMAP, means you will have both an IMAP and SMTP tab in your account settings, you can remove the account from eM Client and then add it again.

Other than that, I have no further suggestions Michael.

The account is IMAP. If i remove the account will I lose all the emails?

No, because with IMAP the messages are stored on the server, and eM Client just gives a cached copy of that. Before deleting the account, go to Menu > File > Backup and make a backup just in case.

By the Server, do you mean Sky/Yahoo?
If so, the the emails have been deleted from there. I store them in Local Folders in eM Client after downloading from the server.

The sky.com server. If you have moved the messages to Local Folders that is OK. Deleting the account from eM Client will not delete anything in Local Folders.

Ok thanks. I will make a back upfirst then try removing the account and adding it again