Exchange virus scan, spam and email security

Hi,

The company I work for had a major spam problem when I joined around a year ago. No spam solution was in place and the AV software had expired on the server.

I now use an external spam filtering service which deals with spam and virus before they enter the company. Fsecure is installed on the server and client machines.

Some spam gets through the system we use. A user noticed one of the spam messages they had recieved had also been sent to an email address which was in thier contacts?
The users mailbox is no longer backing up although I am unsure if the issue is related. I have posted the backup error message at the bottom of the post.

We often receive spam claiming to be from our company. Is this due to the email address being spoofed and is there a way to stop this?

The spam subject often looks like it is picking up information from somewhere as it is very accurate!

Are there any virus scanners I can use to specifically scan exchange or mailboxes for viruses as Fsecure does not find anything?

Fsecure recently removed an infected attachment from an email. On further investigation I noticed the email had not come through our external spam system which should process all emails. Our IT support company said our server had been telneted onto and the email with the attachment had passed through our hardware firewall and been removed by Fsecure for excange!
I tried setting up connection control on the default SMTP virtual server to only accept the IP addresses of our spam filtering service but this stopped laptop users being able to use Outlook Web Access.

Are there any settings I can use in in SBS 2003 to improve email security and spam.

Many thanks for your time,

Chris.

Veritas Backup Exec error message

Backup- \\SERVER\Microsoft Exchange Mailboxes WARNING: “\\SERVER\Microsoft Exchange Mailboxes\Nicky Surname1 [name1]Top of Information StoreSent ItemsŒ〰〰〰〰㔶挲戲㔶㘴愶搹㤴〸㠶愵愶㌱晡㙣挷㜰〰㜲㜱搷㤵愸捣㤸㐴ㅢ㐰㠲戵㜸ㅢ昹ㄸ〰〰〰〰㔲愶〰〰㜲㜱搷㤵愸捣㤸㐴ㅢ㐰㠲戵㜸ㅢ昹ㄸ〰〰〰㠰慤㠴〰〰Deposit on Discovery” is a corrupt file.
This file cannot verify.
WARNING: “\\SERVER\Microsoft Exchange Mailboxes\Nicky Surname1 [name1]Top of Information StoreSent ItemsŒ〰〰〰〰㔶挲戲㔶㘴愶搹㤴〸㠶愵愶㌱晡㙣挷㜰〰㜲㜱搷㤵愸捣㤸㐴ㅢ㐰㠲戵㜸ㅢ昹ㄸ〰〰〰〰㔲愶〰〰㜲㜱搷㤵愸捣㤸㐴ㅢ㐰㠲戵㜸ㅢ昹ㄸ〰〰〰搴㐱戲〰〰RE: Sales Invoice” is a corrupt file.
This file cannot verify.
WARNING: “\\SERVER\Microsoft Exchange Mailboxes\Ray Surname2 [Name2]Top of Information StoreadminŒ〰〰〰〰㉦晣捣㕥换ㅥ慥㔴摢ㄱづ挶㐵戳敡〵㜰〰㝣攴㜴㠱㘶ㅦ㕡㐴㙡戵㈵戹〹攷挵昸〰〰㘰愶〰搲〰〰㝣攴㜴㠱㘶ㅦ㕡㐴㙡戵㈵戹〹攷挵昸〰〰㤰昲〱攰〰〰Deposit on Discovery” is a corrupt file.
This file cannot verify.
Verify- \\SERVER\Microsoft Exchange Mailboxes WARNING: “Deposit on Discovery” is a corrupt file.
This file cannot verify.
WARNING: “RE: Sales Invoice” is a corrupt file.
This file cannot verify.
WARNING: “Deposit on Discovery” is a corrupt file.
This file cannot verify.