Thanks, I did that, and I am still getting rejections. Following is an excerpt from the maillog:
Nov 14 12:42:52 juliet postfix/smtp: 4982A6005B82B: email@example.com, relay=smtp.comcast.net[188.8.131.52]:587, delay=6917, delays=6886/0.07/31/0.15, dsn=5.1.0, status=bounced (host smtp.comcast.net[184.108.40.206] said: 550 5.1.0 firstname.lastname@example.org sender rejected : invalid sender domain (in reply to MAIL FROM command))
Nov 14 12:42:52 juliet postfix/cleanup: 8F04D6005B826: message-id=20171114204252.8F04D6005B826@juliet.deltaecho.lan
Nov 14 12:42:52 juliet postfix/bounce: 4982A6005B82B: sender non-delivery notification: 8F04D6005B826
How do you check the response to helo command? and would that be different from ‘mail from’?
Finally I realized that defining a virtual server was not enough to receive mail from Internet, so I also created mail aiiases for individual users. Since Comcast blocks port 25 I am using a forwarder to send the mail to port 587. I appears that mail is rejected unless I enter the forwarder’s IP in ‘SMTP Access’. Is that correct?