Hi guys, just completed a new ispconfig install and am checking mail server configuration... ISPConfig setupIn Server config>Mail ...Should i "reject sender and login mismatch"? Does this have anything to do with my incoming mail server settings below ie "incoming doesnt require login"? DNS Host Host IP Address = 18.104.22.168 hostname.fqdn = server1.fqdn.com Client domain domain.com - A record - 22.214.171.124 domain.com - MX record - server1.fqdn.com DKMI is enabled and keys exist for domain nameservers are via free dns hosting by domains registrars for both host and client domain. Outlook email client (desktop pc app - office 365) Incoming mail server = domain.com Port 993 Encryption Method = SSL/TLS Does not require Login using Secure Password Authentication (SPA) Outgoing Mail Server = domain.com Port 465 My outgoing (smtp) server requires authentication User same settings as my incoming mail server Why in Microsoft Outlook do emails from this server all say "unchecked"? (this does not happen from my other Virtualmin system) Do i need to manually copy the DKIM to domain.com registrar zone file records? If i have DKIM, are spf and _dmarc still required or is DKIM enough to avoid email client app erros? ( I usually only use spf and _dmarc, this is first time using dkim for me so i wish to understand a bit more about it). With just DKIM, Emails sent to hotmail and outlook are being classed as junk even though DKIM is shown as a pass when i check header tags in Microsoft Outlook Desktop App.