Hi I found a solutions about MX filter in http://rmxf.comm.pl/
On 18.09.2020 01:30, @lbutlr wrote: > On 17 Sep 2020, at 17:03, Fred Morris <m3...@m3047.net> wrote: >> On Thu, 17 Sep 2020, Antonio Leding wrote: >>> TILT: MX records are not required for email to work — WOOT… >> Not required for SPF either. You can list the IP address(es). Of course if >> you have MX then for SPF it's simple "+mx". > This may have changed, but I doubt it. If you do not have MX records there > are definitely mail servers out there that will not send mail to you. > Exchange for one at least used to refuse to deliver mail without an MX > record. I don't know if this is still the case as I am thankfully at least 5 > years from having to deal with anyone on Exchange server. > > >
