Many thanks for the sanity check From: Josef Vybíhal <josef.vybi...@gmail.com> Date: Tuesday, March 8, 2022 at 08:07 To: Daniel White <daniel.e.wh...@nasa.gov> Cc: "postfix-users@postfix.org" <postfix-users@postfix.org> Subject: [EXTERNAL] Re: Firewall Ports
For the smtp, you only need 25. 465 is smtps and 587 submission - sub. 2525 is not needed either. For pure relay the 25 is the only port you need, external mailservers will not relay to any other port, unless specifically configured. Josef On Tue, Mar 8, 2022 at 1:54 PM White, Daniel E. (GSFC-770.0)[NICS] <daniel.e.wh...@nasa.gov<mailto:daniel.e.wh...@nasa.gov>> wrote: For a mail relay server running only Postfix, I am making an educated guess that the only potentially needed open ports would be 25, 465, 587, and 2525 (According to https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsectigostore.com%2Fblog%2Fwhat-is-a-secure-smtp-ssl-port-heres-what-to-know-about-smtp-security%2F&data=04%7C01%7Cdaniel.e.white%40nasa.gov%7Cc6d050bbba2f455bee7308da01048e6a%7C7005d45845be48ae8140d43da96dd17b%7C0%7C0%7C637823416323325480%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=UcwVTm%2BVO00rpRya19KFLjCuPbbWMv%2F8Gvb3Mbv1rJU%3D&reserved=0) No need to open imap(s) and/or pop3(s), right ?
