IIT HELPDESK
ENSURING EMAIL DELIVERABILITY WHILE COMBATING PHISHING
!
ERIC TENDIAN, TENDIAN.IO
is not helpful
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How did we get here?
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But first, who is this random freshman talking to you?
Eric Tendian
Binary Sentinel, CEO, Student
Hi, I’m
@EricTendian on Twitter, Github
Send your spam to [email protected]
Read what I write at eric.tendian.io
HIRE ME at www.tendian.io
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BACKGROUND
INCOMING
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Getting emails delivered:
Easy, right?
Your Mail
Server
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Still easy, right?
AOL
Yahoo
Goog
Live
.edu
Etc…
ISPs
Spam
Folder
Your Mail
Server
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Hmm...
AOL
Yahoo
Goog
Live
.edu
Etc…
ISPs
Spam
Folder
Your Mail
Server
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Um...
AOL
Yahoo
Goog
Live
.edu
Etc…
ISPs
Spam
Folder
Your Mail
Server
Spamhaus
SURBL
Invaluement
CBL
SPAMCOP
Etc…
BlackLists
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Help!
AOL
Yahoo
Goog
Live
.edu
Etc…
ISPs
Spam
Folder
Your Mail
Server
SORBS
BSB
CBL
PSBL
SPAMCOP
Etc…
BlackLists
Goog
McAfee
Mail
Trust
Spam
Assassin
Cloudmark
Etc…
Spam
Filters
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What kinds of email
go through this mess?
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Everything.
But in case you’re
wondering, there’s two
main types of email for
businesses…
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Marketing Email
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Marketing Email
Newsletters,
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Marketing Email
Newsletters,
Promotions,
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Marketing Email
Newsletters,
Promotions,
Mass Announcements,
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Marketing Email
Newsletters,
Promotions,
Mass Announcements,
Other mass emails
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Marketing Email
Newsletters,
Promotions,
Mass Announcements,
Other mass emails
One-to-Many
Did you know:
20% of email
never arrives.
*According to Return Path research study on commercial email
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Why is this?
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SPF
SMTP
Dedicated IP
IP History
DNS Setup
Domain History
DKIM
DMARC
Honeypot
abuse@
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Standard spam filter
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Standard spam filter
Tests for:
• Strange/malformed headers
• Spam-like wording in the message body
• Mentions of common spam keywords
• Cialis, Viagra, etc.
• Misspellings of words
Scored and ranked to generate a “spam score”
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Sender Identification
“Did you really send this?”
SPF DKIM
DMARC
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Holy Trinity of Email Security:
SPF+DKIM+DMARC
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“I use all three! I’m fully
protected now, right?”
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REPUTATION
MATTERS
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IP Reputation
169.254.219.226 169.254.219.226
Shared IP Dedicated IP
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BLACKLISTS
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How do I end up on a blacklist?
Spam Traps!
a.k.a. honeypots
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Okay, let’s review
• Standard spam filter: regex tests
• DNS tests
• SPF, “I give you permission” - good
• DKIM, “email key exchange” - better
• DMARC, “did SPF and DKIM pass?” - best
• Shared server? Watch your rep
• Caught by spam trap? Blacklisted
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So how do we get rid
of “IIT HELPDESK”?
TIPS & TRICKS INCOMING
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CAN-SPAM Act Compliance
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
✓ Don’t use deceptive subject lines
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
✓ Don’t use deceptive subject lines
✓ Identify the message as an advertisement
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
✓ Don’t use deceptive subject lines
✓ Identify the message as an advertisement
✓ Tell recipients where you’re located
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
✓ Don’t use deceptive subject lines
✓ Identify the message as an advertisement
✓ Tell recipients where you’re located
✓ Tell recipients how to opt out of receiving future
email from you (unsubscribe link clearly
displayed)
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
✓ Don’t use deceptive subject lines
✓ Identify the message as an advertisement
✓ Tell recipients where you’re located
✓ Tell recipients how to opt out of receiving future
email from you (unsubscribe link clearly
displayed)
✓ Honor opt-out requests promptly
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CAN-SPAM Act Compliance
✓ Don’t use false or misleading header information
✓ Don’t use deceptive subject lines
✓ Identify the message as an advertisement
✓ Tell recipients where you’re located
✓ Tell recipients how to opt out of receiving future
email from you (unsubscribe link clearly
displayed)
✓ Honor opt-out requests promptly
✓ Monitor what others are doing on your behalf
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Simple Tips/Tricks
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Simple Tips/Tricks
✓ Shared IP Address?
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Simple Tips/Tricks
✓ Shared IP Address?
✓ Check IP address for previous abuse (on
blacklists? use reputation lookup tools)
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Simple Tips/Tricks
✓ Shared IP Address?
✓ Check IP address for previous abuse (on
blacklists? use reputation lookup tools)
✓ Setup postmaster@, abuse@, etc.
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Simple Tips/Tricks
✓ Shared IP Address?
✓ Check IP address for previous abuse (on
blacklists? use reputation lookup tools)
✓ Setup postmaster@, abuse@, etc.
✓ Make sure DNS registration is up-to-date
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Simple Tips/Tricks
✓ Shared IP Address?
✓ Check IP address for previous abuse (on
blacklists? use reputation lookup tools)
✓ Setup postmaster@, abuse@, etc.
✓ Make sure DNS registration is up-to-date
✓ Unsubscribe links added?
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Complex Tips/Tricks
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Complex Tips/Tricks
✓ Use SPF, DKIM, and DMARC
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Complex Tips/Tricks
✓ Use SPF, DKIM, and DMARC
✓ Keep spam filters updated w/ custom tests
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Complex Tips/Tricks
✓ Use SPF, DKIM, and DMARC
✓ Keep spam filters updated w/ custom tests
✓ Check blacklists regularly
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Complex Tips/Tricks
✓ Use SPF, DKIM, and DMARC
✓ Keep spam filters updated w/ custom tests
✓ Check blacklists regularly
✓ Make your own spam trap
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Complex Tips/Tricks
✓ Use SPF, DKIM, and DMARC
✓ Keep spam filters updated w/ custom tests
✓ Check blacklists regularly
✓ Make your own spam trap
✓ Use managed email solutions when
possible
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Complex Tips/Tricks
✓ Use SPF, DKIM, and DMARC
✓ Keep spam filters updated w/ custom tests
✓ Check blacklists regularly
✓ Make your own spam trap
✓ Use managed email solutions when
possible
✓ Include tracking in all emails to check
deliverability
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Feedback is important
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Strive for…
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Strive for…
Right Message
to the
Right Person
at the
Right Time
with the
Right Frequency