Outbound Mail Relay HOWTO

Before ordering OMR, consider your daily email volume needs. It is a good idea to pad that estimation, or add more to that value. Uses of your email system may send more email than anticipated when using features such as email forwarding, reply to all, large file attachments, and so on.

If you exceed your OMR data plan, OMR will not accept additional email, so email will stop. Because email stops, you simply can not accidentally overrun quota and there is no expensive surprise 'data overcharge'. OMR accounts may also be upgraded.

The next OMR decision is the account type: Standalone OMR or Hostname OMR. The two account types differ only in the details of how TZO will detect your Internet IP address.

To select a Standalone OMR account type, on the OMR order form leave your domain name BLANK (provide only your email address). Your OMR account name will be in the form of your.email.address.omr, and this type of OMR account will work independently of any DNS records. If unsure, the Standalone OMR choice is safer.

Hostname OMR is a configuration where OMR will be instructed to accept email from the IP address set in an existing TZO domain (or subdomain). Provide the requested hostname, email address associated with that address and then press Continue. On the following order page you will be asked for the TZO Key for that domain. Upon order completion the TZO service will be added onto the DNS service for your network, allowing you to send email from that network.

For any configuration, TZO OMR needs to know what Internet (WAN) IP it should accept mail from. If your ISP gives you a dynamic IP address, you must install a TZO client such as TZO Lite. For static IP Internet connections you can just set your OMR account to your current Internet WAN IP. For a Hostname OMR configuration, you will already have a TZO domain which points to the network you will send email from.

If you exceed your OMR plan's daily limit, email will stop and your email software should record this error. Additionally, TZO will email you a notification of this event so you are aware of the problem. Without intervention, email will begin re-flowing at midnight (Eastern US time) when the daily quota starts anew.

Except when the quota was due to a bulk email or notification issue, you may upgrade your OMR plan. The Hourly Quota is 50% of your daily quota, so it should not ever be encountered unless there is some other problem ongoing. If you are having a problem with quotas please contact TZO Support.

What happens if OMR rejects my message?

In the event your email was flagged as spam or virus, the following occurs: OMR will reject the message with a SMTP 500. As the email will never have been delivered to OMR, there will be no 'bounce' message from OMR but your own email software would have recorded the error.

If you believe the email rejection was in error, please notify TZO Support and include the full headers of the email.

My email bounced. Why?

OMR does not bounce email on its own, so if this happens it is because your recipient rejected your message. In this event, OMR will send you a bounce message if the recipient's mailserver refusal.

Please note the OMR bounce notice will quote the full SMTP Error and Error Text, verbatim as provided by the recipient's mailserver. TZO can not affect another site's spam filter policy. If you are unsure what the SMTP error means, please contact TZO Support. The referenced error message is provided by OMR to assist your email administrator (or the recipient's administrator) resolve the error.

My email was not delivered. Where is it?

First check your email software logs to be sure the message was accepted by OMR. If the email was accepted by OMR, then OMR would dutifully route the email to the recipient's mailserver.

If the recipient's mailserver accepted the email, OMR will record this as part of our SMTP logging. If the recipient's mailserver rejected the email, this will also be logged (and you will be sent a bounce).

In rare events, the recipient's mailserver might not be answering delivery requests, or have disk-full errors, etc. In this case OMR will 'retry' delivery several times per hour, for up to 24 hours before aborting and sending you a bounce notice.

How many recipient's can I address on an email?

TZO OMR policy allows 200 recipients per email message. However, large mailing lists should ideally be configured to send email in blocks of 100 recipients per email envelope so as to avoid delays or errors imposed by third parties.

Note that many of the large 'free' email providers such as Yahoo do not like email which contains 'many' recipients, and the number varies. The recipient's mailserver may impose delays on such email.

Does OMR count quotas for Bcc: or CC: differently than To:?

For the purposes of OMR quota accounting, a 'To:', 'CC:' or 'Bcc:' are all counted the same.

OMR refuses my email with a 'Sender Verify' error. Why?

To limit potential for abuse, OMR does not accept mail with a bogus or forged 'From:' address. The Sender Verify test will contact the mailserver of the domain in the From: address, verifying that claimed From: address actually exists.

If this error occurs, most often it is due to a typo error in your email's From: address. In rare cases this problem can occur when the mailbox exists, but the sender domain suffers from a previously undiagnosed error in domain of the sender's From address. (An example of such a problem would be hardcoded IP addresses in the sender's MX record set, or other RFC violations).