SureMail: Notification Overlay for Email Reliability

1
SureMail Notification Overlay for Email
Reliability
Sharad Agarwal, Dilip A. Joseph, Venkat
Padmanabhan http//netprofiler

• Email Loss Delay
• Why ?
• Aggressive spam filters
• Upgrades/downtime/failure
• 90 email to MSFT tossed !
• Often silent(no bouncebacks)
• Delay can be as bad as loss

• SureMail Architecture
• Client-based approach
• No server mods., no PKI
• Separate notification overlay
• Sender post notification
• Recipient Youve lost mail

• Notification Format
• Receiver hash H(R)
• Time to live T
• Email body hash H(Mnew)
• Shared secret H(Mold)
• Authenticator MAC(T,H(Mnew), H(Mold))
• Hard for spammer to spoof

• Experiment
• 36 sending email accounts
• 42 receiving email accounts
• MSFT, EDU, Hotmail, Yahoo, , US, UK, AU, NZ, CA
  
• Enron corpus (1266 bodies)
• Attachments (DOC, JPG,)

• Salient Features
• Minimal disruption
• Minimal demands on user
• Preserves asynchronous comm., privacy,
  repudiability
• Maintains spam, virus defense
• Low overhead

• Results
• 83 days
• 158,379 emails sent
• 3,183 emails lost
• Loss rate 1.82 to 3.36
• Silent loss 0.71 to 0.91
• Delay mean 276 seconds
• max 36.6 hours

• Status
• Prototype implementation
• Run SureMail experiment
• 29 days, 19435 emails sent
• All 653 lost emails caught!
• HotNets 2005 paper
• Patent application pending

• Key Mechanisms
• Email-based handshake
• Prevents impersonation
• Reply-based shared secret
• Blocks notification spam
• Automatic reply detection
• Based on text similarity

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