Service Diagrams
Click images to enlarge.
Scenario 1
Scenario 1 shows mail delivery to a
single mail server which is correctly working.
Scenario 2
Scenario 2 shows the same setup with
the destination server offline. Without Mail Store &
Forward important emails can be lost.
Scenario 3
Scenario 3 shows a correctly working
server setup with a Mail Store & Forward solution in place
ready in the event of the destination email server going offline.
While it is online the destination server regularly sends requests
to the Store & Forward server for any emails that may be
queued.
Scenario 4
Finally, Scenario 4 shows mail
delivery to the Store & Forward server as the primary server is
offline. Mails are queued on the Store & Forward server until
the primary server is again online. Once the primary server is
online it resumes the regular requests for any emails which
are queued, at which time all the emails on the Store & Forward
server are delivered and normal service resumes as shown in
Scenario 3.