
Ask HN: Wasn't e-mail deliverability affected today for domains hosted with dyn? - nodesocket
If you tried to send an e-mail to foo@twitter.com during the dyn outage, would the message be delivered? Perhaps delivered eventually (delayed).
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pwg
> Perhaps delivered eventually (delayed).

This is how email is designed. Mail servers will continue to try to deliver
for quite some time before giving up.

The email transmission protocol was designed way back in the day of
intermittent internet connections, so it has already backed into its design
the concept of retry some number of times before giving up.

FWIW, twitter uses google as their email:

    
    
        twitter.com     mail exchanger = 30 ASPMX3.GOOGLEMAIL.com.
        twitter.com     mail exchanger = 20 alt2.aspmx.l.google.com.
        twitter.com     mail exchanger = 30 ASPMX2.GOOGLEMAIL.com.
        twitter.com     mail exchanger = 20 alt1.aspmx.l.google.com.
        twitter.com     mail exchanger = 10 aspmx.l.google.com.
    

So anyone who had twitter's MX records cached in their local DNS servers would
never have noticed a problem from the dyn outage (as least not until the cache
expired).

