Email Server Redundancy

Email Server Redundancy

How Email Delivery Works

When an email is sent to a recipient the email server looks to see which server handles mail for the domain using the DNS MX records. MX records specify which server(s) will receive mail for a given domain. Each MX record is given a priority (the MX level), the lowest number being the primary mail server. The primary mail server is responsible for delivering the mail to the appropriate user mailbox.

Mail delivery is first attempted to the primary mail server (indicated by the MX record with the lowest MX priority number). If that server is not reachable, then delivery is attempted to the mail server with the second lowest MX priority number. If the second lowest mail server in priority is unreachable, then the mail will be delivered to the server with the third lowest MX priority, etc.

How Email Server Redundancy works

ShenValley's email server redundancy back-up emails to three additional enterprise email server clusters for complete email redundancy.

If your mail server cannot be reached, then your email is sent to ShenValley's Enterprise Redundancy email servers. Once it reaches our servers, it remains in queue and we continually reattempt delivery of the mail to your primary mail server. When your primary server is back online, the queued mail is instantly delivered to your mail server. ShenValley's will keep attempting to deliver mail to your server for 14 days or until it responds.

Quotas and Limitations per domain

  • Each Domain is allowed 1 GB of email or 100,000 messages in queue. 3GB, 5GB, and 10GB options are also available for an additional fee.
  • Each domain is allowed to transfer 10 GB of email per month.
  • There is also a daily limit of 100,000 incoming connections per day.
  • We can not be used to defend a dictionary / directory harvest attack.
  • Emergency Email Spooling
  • 24/7 Web Support Included
  • 10,000 Messages Per Day Queued
  • Incoming Email
    • 1,000 MB per Day
    • 1,000 MB Max Queued

ShenValley's redundant email service is not an anti-spam service. However, we do perform simple email checking to help prevent spammers from using our emails servers as an open relay to your mail servers.

  • Verify the server sending the email has correct reverse DNS configured.
  • Check to make sure the “from” mail address is valid.
  • Check to make sure the email headers are properly formatted.
  • Utilize Greylisting
  • Utilize the Spamhaus RBL as well as an internal RBL.

The rate is an annual rate and will be renewed automatically unless cancelled.