Marrickville, NSW

Cintia

Robbie,

Launceston, TAS

Marrickville, NSW

Robbie,

Launceston, TAS

Trust in Post Offices

cintia@unsw.edu.au

to: robbie@utas.edu.au

unsw.edu.au

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

cintia@unsw.edu.au

robbie@utas.edu.au

utas.edu.au

unsw.edu.au

Trust in Email Providers

Email Provider trust

• SPF

• DKIM

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

cintia@unsw.edu.au

robbie@utas.edu.au

utas.edu.au

unsw.edu.au

SPF

unsw.edu.au domain uses following IPs for sending emails

DKIM

unsw.edu.au uses following signature for sending emails

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

cintia@unsw.edu.au

robbie@utas.edu.au

utas.edu.au

unsw.edu.au

From where?

• Email Provider From (MFrom)
• User-friendly From

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

mFrom: server@unsw.edu.au

cintia@unsw.edu.au

robbie@utas.edu.au

utas.edu.au

unsw.edu.au

SPF and DKIM

ONLY Email Provider

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

mFrom: server@unsw.edu.au

cintia@unsw.edu.au

robbie@utas.edu.au

utas.edu.au

unsw.edu.au

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

mfrom:hacker@badserver.com

robbie@utas.edu.au

badserver.com

utas.edu.au

to: robbie@gmail.com

from: sales@mycompany.com

mfrom:server@rezdy.com

robbie@gmail.com

rezdy.com

gmail.com

DMARC

Compares the user friendly from with email provider

DMARC

something@unsw.edu.au can only come from something that matches SPF or DKIM 

to: robbie@utas.edu.au

from: cintia@unsw.edu.au

mFrom: server@unsw.edu.au

cintia@unsw.edu.au

robbie@utas.edu.au

utas.edu.au

unsw.edu.au

DMARC

• None
• Quarantine
• Reject

DMARC

something@rezdy.com can only come from something that matches SPF or DKIM 

SPF

rezdy.com uses following IPs for sending emails

DKIM

rezdy.com uses following signature for sending emails

to: robbie@gmail.com

from: sales@mycompany.com

mfrom:server@rezdy.com

robbie@gmail.com

rezdy.com

gmail.com