E-Mail Protection Functionality

• Basic Functionality of the LinuxForce Email Protection Service
• Exim4 mail server (port 25 and 587)
• POP (Post Office Protocol) mail retrieval to users POP mail accounts
• Password (poppassd) change server for Eudora, NUPOP, and squirrelmail
• Incoming SMTP mail delivery to POP mail accounts and aliases to support routing of role accounts and multiple identities
• Outgoing SMTP mail delivery service to users on your private LAN (Local Area Network)
• Support for outgoing authenticated SMTP mail delivery service to users who provide their POP account username and password
• Support for TLS (Transport Layer Security) to encrypt mail delivery (for exchange of e-mail with sites that support TLS)
• Web Mail functionality provided by squirrelmail (SquirreIMail-Plugins)
• A sampling of SMPT-time ACLs (Access Control Lists)
  • dns lookups (will cause a delay if misconfigured; the delays trigger some badly written spambots into triggering other ACLs
  • helo verification
  • check actual helo for forgery or if bare ip used (rfc violation)
  • check that helo was said before mail from:
  • accept relay hosts (if any)
  • accept authenticated senders
  • reject non-authenticated senders on port 587
  • defer dictionary attacks
  • reject invalid local email addresses
  • accept postmaster
  • reject mail pretending to be from a system account at our domain(s)
  • reject mail that says helo as the domain it is sending to
  • sender verify callouts
  • reject locally blacklisted hosts/senders/domains
  • accept relay hosts (MTA's (Mail Transport Agent))
  • greylist "suspicious" connections
  • Check RBL's (Realtime Blackhole List) and reject if listed too many times, greylist if listed at all
  • evaluate headers of email (reject if obvious forgeries or greylist if it feels "spammy")
  • heuristic rejection of spam-like email
  • reject DSN's (Delivery Status Notification) for role accounts
• Content Filtering
• mime tests (reject insecure file extensions, invalid formatting)
• file type based rejection
• ClamAV for anti-virus
• Scanning into multiple archives
• Mutated Aho Corasick algorithm (very fast scanning)
• Multi-threading, autodetecting the number of CPU
• Spamassasin for spam scanning
  • Score based, rather than single accept/fail rules
  • Network tests
  • Regular expression matches
  • Naive bayesian database

For more information on LinuxForce's email protection services, e-mail us or call us at 610-734-1900.

Follow this link to return to the Main Page on our E-Mail Protection services.