What happens to your email when your email service is interrupted for some reason? With Ultratek's Backup Email Service, all your email is returned when your server comes back on line. You never have to worry about lost email.
Here's how Ultratek's backup email service works.
We set up your domain name on one of our backup mail servers.
We add a secondary MX record to your DNS (pointing to the backup mail server).
If a sender cannot contact your primary email server, the message is delivered to the secondary server.
Our backup email server stores the message and attempts to forward it to your server.
Our backup server will store your messages for up to 5 days and attempt delivery every 6 hours. When your mail server comes back on line after an outage, your accumulated email gets delivered within 6 hours.
Technical Background
When an email client sends an email, it looks up the domain's DNS to determine the mail exchangers (MX) for the domain. Each MX record is given a preference number and the lowest becomes the primary mail server.
Mail delivery is first attempted on the lowest preference number MX. If the delivery fails, it tries the second lowest preference MX and so on. If no mail servers can be reached, the mail is bounced back to the sender.
A Backup MX Server is a mail server that stores (spools) your incoming email when your primary mail server becomes unavailable. A mail server can become unavailable to receive incoming mail for a number of reasons, including:
A hardware or software failure
Being very busy and unable to receive new incoming connections or emails
The network connection is down or saturated
Network routing issues
Without a Backup Server
If you do not have a Backup MX Server, the following can occur:
The email is bounced (Returned to Sender)
Inbound email will cause a backup in the originating mail server's spool
Service Timeout; Depending on the Retry attempts by the originating mail server, your mailboxes may never receive their incoming email
Users do not understand bounce messages; to most users, bounce messages are unreadable, so when they can't send an email, they do not try to resend.
With a Backup Server
When you have a Backup MX Server:
1. A user sends email to
(a mailbox hosted by Ultratek)
2. The originating mail server looks up the MX Records for youremail.com and finds two:
IP: x.x.x.x Weight: 10
IP: y.y.y.y Weight: 20
3. The originating mail server first attempts to connect to: x.x.x.x
4. The connection fails for some reason.
5. The originating server tries to connect to the secondary MX record: y.y.y.y
6. It successfully connects to this server.
7. Email transmission begins, and the Backup MX Server receives the email into its spool.
8. Since there are no existing local domains on this server, Ultratek stores this email in its spool.
9. Based on of the Retry Attempts, Ultratek will continue to make connections to your Primary Mail Server.
10. Ultratek will make only 4 retry attempts, the last attempt 24 hours later.
This way Ultratek does not send a Bounce Message to the originator saying that it could not deliver the message before your Primary Server is back online.
11. If your Primary Mail Server comes back online before the final Retry Attempt, the Retry Counts are reset on all messages in the spool. This will force the Backup MX Server to forward all existing mail in the spool back to your Primary Mail Server.
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