SBS – No Incoming Mail ‘421 4.3.2 Service not available’
KB ID 0000803 Problem While testing mail flow on a new SBS 2011 Server, outbound mail worked fine, but no mail would flow in. When I attempted to Telnet in from a remote host this was what I saw; 421 4.3.2 Service not available Connection to host lost. Solution Normally I’d expect to see an error like this if the Exchange ‘Receive Connector’ was misconfigured, (if you’re not using SBS 2011 create a new default...
Exchange 2019, 2016, 2013 – Allowing a Host/IP to Relay Mail
KB ID 0000891 Problem There a a few more hoops to jump through to allow a host to relay though Exchange 2013. For earlier versions of Exchange see the links below. Allow Relay from an IP With Office 365 (Exchange Online) Allow Relay from an IP with Exchange 2010 Allow Relay from an IP with Exchange 2007 Allow Relay from an IP with Exchange 2003 Allow Relay from an IP with Exchange 2000 Solution How to create a ‘Relay’...