Skyway West refuses E-mail sent from known sources of SPAM to email accounts we host. We also refuse mail sent from domains that do not resolve properly because this is a common indication of spam. If you are sending a vailid email, we are very sorry for any inconvenience our spam prevention efforts might cause you. It may be that your outgoing mail server is using a TCP/IP address known as a likely source of SPAM or exhibiting characteristics common to spammers.

Based on the error message our server issued, which should be included in the bounce message you received, this page will attempt to explain why your message was refused and what you (or more likely the administrator of your E-mail server), can do to fix the problem so you can send E-mail to our customers in the future.

If you are running Microsoft Exchange, the bounce you receive will not contain any useful information. One of the problems with Exchange is that it does not include useful error messages in bounce reports. Your E-mail administrator should see this section to try to figure out why your E-mail was refused. This section is also applicable to administrators of any other mail server that discards error messages issued by recieving servers.

Possible error messages you might see and what they mean:

451 Domain of sender address does not resolve (see below: “Email from Non-resolvable Domains”)
571 Mail from xx.xx.xx.xx rejected see
571 Mail from xx.xx.xx.xx rejected see See Skyway Support article: Osirusoft Relays
571 Mail from xx.xx.xx.xx rejected see
571 Mail from xx.xx.xx.xx rejected see


SPAM is often sent from a forged domain name and hence we refuse E-mail if we cannot confirm or resolve the domain of the sender. If your domain cannot be resolved because it has expired or for some other reason, you cannot can send E-mail to accounts hosted by Skyway or anybody else.

The domain portion of your E-mail address is the part after ” @” . “To resolve” means that we must be able to locate an MX (Mail eXchanger) or A (Address) record within the global Domain Name System (DNS) for your domain. If we cannot, we issue a temporary failure notice saying we will continue trying to deliver your email. Your mail server may return our message to you or redirect it to the server’s administrator.

We also refuse email without a fully qualified domain name (FQDN). A fully qualified domain name is one where the name of the sending mailserver contained in the email headers matches the name in the MX record. If the two do not match, our mail server replies that it cannot accept your mail because your mail server lacks a fully qualified hostname in the SMTP HELO (it may also use EHLO). If we are rejecting your email because this problem, the person managing your outgoing mail server or the company hosting your domain and MX record must ensure their records match. This is easily done.

Don’t worry, we know the above sounded like techno-babble. However, it will make sense to anyone qualified to provide the DNS for your domain name.

Once the problems with your DNS entries are corrected, you will have no problems sending E-mail to accounts we host.

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