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.
ShenValley’s back-up email service provides access to three (3) 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 Back-up 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.
ShenValley’s back-up 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.