- When a user tries to open a mail database that is unavailable
Failover for mail works the same as for any database.
- When a user tries to send a message after the user's mail server has become unavailable
If a user is composing a message when the mail server becomes unavailable, the user can still send the message. The delivery fails over to another cluster server, where Notes deposits the message in the outgoing mailbox. Saving the message does not fail over, however, so this message is not saved in the sender's Sent folder.
- When the router tries to deliver mail to a server that is unavailable
If the server that contains the mail database is unavailable, the router delivers the mail to a cluster server that contains a replica mail database. The router uses the following process to find the correct mail database.
First, the router checks to see if mail routing failover is enabled for the local server and if the user's mail server is in a cluster. If the local server is in the same cluster and has a replica of the user's mail database, the router delivers the mail to that database. Otherwise, it asks an available cluster member for a server that contains a replica of the user's mail database, and delivers the mail to that database. If there is no replica available, the router tries again to deliver the mail to the user's mail server without using failover.
- When the user is using shared mail
Shared mail works the same on a cluster server as it does on a non-clustered server. When a user opens a shared message in a replica of the user’s mail database, Domino opens the message header from the user's mail database and opens the message body from the shared mail database on that server.
When the Cluster Replicator replicates a new message to another replica of the mail database, the Cluster Replicator combines the message header and message body together as one note and sends the note to the cluster server where the replica resides. The receiving server determines if shared mail is being used. If shared mail is being used, the server deposits the message header in the replica of the user’s mail database and deposits the message body in the shared mail database on the server. If shared mail is not being used, the server deposits the entire message in the replica of the user’s mail database.