This likely means SMTP authentication is not enabled. If you get a relay denied error and your password is correct, then SMTP authentications is likely not correct. Often, email users with this issue can receive but cannot send email.
Association for Progressive CommunicationsThe usual symptom is that Thunderbird will try to send for about 20 seconds before giving up with "Sending of message failed. The message could not be sent ...
support.hostgator.com > ... > Email > Email Troubleshooting
If you aren't able to send email, this usually means one thing: your internet provider is blocking you from using anyone's outgoing mail servers but their own. ... so that theycan monitor outgoing email on their network in order to prevent spam.
www.inmotionhosting.com > ... > Email > Email Troubleshooting
Jan 14, 2015 - Outlook 2013, cannot send mail, but can receive mail ... I haven'treceive any mail since yesterday and I can't send mails too... can you help me ...
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