sandbox.l.google.com.

142.250.158.81
nf-in-f81.1e100.net

sandbox.l.google.com.
2607:f8b0:4003:c3e::451

alt1.gmr-smtp-in.l.google.com.
alt2.gmr-smtp-in.l.google.com.
alt3.gmr-smtp-in.l.google.com.
alt4.gmr-smtp-in.l.google.com.
gmr-smtp-in.l.google.com.
sandbox.l.google.com.