Inbound Routing With Secondary Mail Service
A. Unprotected Routing with Exposed Secondary Mail Service
If a failure occurs between the Internet and the Primary Mail Server, messages are diverted by DNS to the Secondary Mail Server, where they are held until the Primary Mail Server is once again able to accept e-mail.
Analysis: Dangerously ill-advised method for messaging.
B. Routing with trimMail Inbox and
Exposed Secondary Mail Service
- Inbound SMTP mail goes to trimMail Inbox, where it is tagged for spam and cleansed of scripts and other potentially dangerous contents. By transferring only those messages destined for the specified mail server, trimMail Inbox prevents spammers from using the mail server as an open relay. The Primary Mail Server then collects all mail destined for its e-mail clients from trimMail Inbox. Outbound e-mail is routed directly from the Primary Mail Server to the Internet.
- If a failure occurs between the Internet and the trimMail Inbox, messages are diverted by DNS to the Secondary Mail Server, where they are held until trimMail Inbox is once again able to accept e-mail.
- If a disruption takes place between trimMail Inbox and the Primary Mail Server, messages are held by trimMail Inbox until the Primary Mail Server can again accept mail. If trimMail Inbox fills up or reaches the time-out set by the Administrator, messages are diverted by DNS to the Secondary Mail Server, where they are held until the Primary Mail Server gets its stored mail from trimMail Inbox, which frees trimMail Inbox to once again accept e-mail.
Analysis: If primary route fails, messages are still tagged for spam and cleaned before hitting Primary Mail Server.
C. Routing with trimMail Inbox and
trimMail Inbox Backup Service
- If Internet-to-trimMail Inbox communication is unavailable, e-mail is diverted by DNS to trimMail Inbox Backup Mail Service which tags and cleanses e-mail then passes it to the Primary Mail Server until in-house trimMail Inbox returns to on-line condition.
- If communications break down between trimMail Inbox and the Primary Mail Server, messages are held by trimMail Inbox until the Primary Mail Server can again accept mail. If trimMail Inbox fills up or reaches the time-out set by the Administrator, messages are diverted by DNS to trimMail Inbox Backup Mail Service which tags and cleanses e-mail then passes it to the Primary Mail Server until the Primary Mail Server can again get its stored mail from trimMail Inbox, which then frees trimMail Inbox to once again accept e-mail.
Analysis: If route to in-house trimMail Inbox fails, messages are still cleaned and delivered to Primary Mail Server until full primary mail route is restored.
D. Routing with trimMail Inbox and
trimMail Inbox Backup Service Assisted
by Exposed Secondary Mail Service
- If Internet-to-trimMail Inbox communication is unavailable, e-mail is diverted by DNS to trimMail Inbox Backup Mail Service which tags and cleanses e-mail then passes it to the Primary Mail Server until in-house trimMail Inbox returns to on-line condition.
- If Internet-to-trimMail Inbox and Internet-to-trimMail Inbox Backup Mail Service communication are both rendered unavailable, e-mail is diverted by DNS to Secondary Mail Server which gives it to trimMail Inbox for cleansing when the system returns to on-line condition. When the system is back on-line, e-mail is again passed through trimMail Inbox before reaching end-users.
Analysis: Three geographically dispersed systems must fail simultaneously before your inbound e-mail cannot be tagged for spam and scoured for dangerous HTML contents and delivered.
|