> On Feb 15, 2017, at 2:10 AM, Henry <der...@gmail.com> wrote: > > When I send a message to Gmail I am informed that it could not be > authenticated and will probably end in the spam folder.
This is largely misinformation. Sites that send bulk mail that might get classified as junk may benefit from DKIM signing and SPF records provided they also enroll in some kind of whitelisting program that requires such measures. Otherwise, since both DKIM and SPF are used as much by spammers as by non-spammers, there is no hard requirement to use these. My domain does not use either. "Authentication" in the context of sending mail means either or both of DKIM or SPF. > I understand > the resolution to this is to obtain an SSL certificate and configure > postfix to use that certificate. That simply wrong. Certificates have no bearing on outbound deliverability. http://postfix.1071664.n5.nabble.com/Best-way-to-run-Postfix-on-a-single-server-for-multiple-domains-td88720.html#a88811 -- Viktor.
