Thanks Mark and Brian. I'll try the suggestions.
My IP might have got blocked by CBL when testing mailman3 against a Gmail address. I have since removed it from CBL. I don't know how my IP got into the Outlook's block list. Maybe a used one. Will try DKIM signing and Microsoft programs.
On 23/11/2020 11:59 am, Brian Carpenter wrote:
On 11/22/20 6:54 PM, Henry S wrote:
Now I am trying to figure out how to configure mailman+postfix to pass the unnecessarily convoluted world of spam-free certification and ip blockings by those 'security lawmakers'.
Any suggestions on how to not be blocked by gmail, hotmail, etc? I have used DKIM (no signing yet), SPF, DMARC to no avail. Maybe not an appropriate question to this mailman list.
Mark Sapiro provided some very good suggestions.
Is this a new IP address or one that has been used for mail traffic for a white? The only way Gmail and Hotmail will block an IP address is if you have some major outgoing spamming problems or in the case of a new IP address, the IP address has a sordid history which will be reveal if you do a RBL check on it.
Gmail likes SPF records and MTA's that utilizes SSL for outbound mail.
For Hotmail deliveries, you will want to signed up for Microsoft's Smart Network Data Service (SNDS) program which I find very good. Also sign up for their JMRP program for your IP address.