Question : sendmail setup for bastion servers

hi,
     i am not that expert in sendmail, but i try to manage :)
now this is my setup
i have two mail servers, one in my internal network, users will check it out for their mails, and one in my dmz area, which will be used as mail gateway to internet.
any incoming mail will come to bastion ---> then to my internal mail server
and outgoing will go from my internal server ---> to bastion server and then to internet.
my question as follows
i am using redhat 7.1 and sendmail 8.11.2
q1:if anything happen and the bastion could not communicate with the internal serves, the e-mails will still waiting on the server(bastion) or they will be backed to source with msg, could not send for 4 hours..or somthing...i want to keep it on the server until problem solved...
q2: i have macfee antivirus installed on server, can i scan e-mails before sending them to internal mail servers..

thankx

Answer : sendmail setup for bastion servers

As to q1, your mail relay box will continue to accept and spool messages for later delivery. It won't start refusing in-bound emails until it runs out of spool space. As soon as the mail relay box notices that the inside server is again accessible it will transfer all of the spooled email to your inside mail server.

As to q2. See http://www.amavis.org/ for one solution that will aloow you to scan emails for virus with McAffe