Sending email through Microsoft Outlook returns a bounce message containing the following reason:
"503 valid RCPT command must precede DATA"
The "Test Account Settings" button in Microsoft Outlook returns the following error:
Send test e-mail message: Unable to send test Message. Please verify the E-mail Address field.
Sending email through Mozilla Thunderbird returns the following error:
"An error occurred while sending mail. The mail server responded: The recipient cannot be verified. Please check all recipients of this message to verify they are valid. Please verify that your email address is correct in your Mail preferences and try again."
This error means that you will need to enable SMTP Authentication in your email client. When your Desktop email client attempts to send an email from our server it must authenticate. The Username and Password you would use would be the same as your incoming username and password.
Recommended Help Content
Why do I receive error "503 valid RCPT command must precede DATA" when attempting to send email? (updated 1726 days ago)
Trying to send out emails from multiple email accounts fail from both webmail and third party email clients. Possible Reasons: The maximum emails per hour has been exceeded. This can be caused by forw (updated 1647 days ago)
Explanantion as to what causes this the happen and how to fix it. (updated 801 days ago)
Related Help Content
I send an email to one person and then do a carbon copy (Cc) to multiple other people. Not everyone is receiving the email, even when I try using blind carbon copy (Bcc). (updated 648 days ago)
You can use autoresponders to send a message back automatically to anyone who sends an email to a certain account. This can be useful for times when you are on vacation or unavailable, or if you have a generic message that you wish to send for a support email address. (updated 801 days ago)
Formmail from Matt's Script Archive will not send from an email address other than my main HostMonster account. (updated 1692 days ago)
Can I send an email with large files/attachments? (updated 346 days ago)
Description of what the error means and how to fix it. (updated 151 days ago)
. Click the RoundCube logo. This takes you to the main interface screen for RoundCube where your Inbox will be displayed. On the left are your email folders, by default, RoundCube will always show you (updated 1215 days ago)
Why can I not send/receive certain types of attachment? (updated 1984 days ago)
You can try sending the email on port 26, which is an alternate SMTP port and see if that works for you. For outlook: (updated 697 days ago)