On Mon, Sep 13, 2021 at 07:58:26AM -0400, Wietse Venema wrote: > > When a user clicks "send", the email client has to make some > > tcp-connection to some ip address. What if the hostname configured > > at the email client resolves to multiple ip addresses? > > It just seems unlikely that major email service providers would run > all their submission services on a single IP address.
With "smtp.gmail.com" one IP address is returned at a time, but it appears to be GeoIP-dependent: NYC: smtp.gmail.com. IN A 209.85.232.109 ; 15ms RTT LA: smtp.gmail.com. IN A 142.251.2.108 ; 8ms RTT München smtp.gmail.com. IN A 108.177.119.109 ; 15ms RTT -- Viktor.