Description

When dealing with Email continuity fail-over there are 2 scenarios to concern yourself with.

1. The mail server is on but cannot accept mail (for whatever reason). SMTP protocol dictates, if the server accepts a connection, the server is 'up'. There is really nothing our service can do to prevent a bounce-back to sender in this scenario; as the server accepted a connection from us - it is seen as a valid relay, despite the error shortly after. Messages in this scenario will either bounce or go into retry.

What we recommend in this scenario is: close port 25 on the firewall if your server is clearly having issues and keep it offline until fixed. If you do this then the connection from the gateway will fail-over to the Email continuity service.

2. In an outage situation: 'power failure' 'server downtime/maintenance' 'DNS or ISP issue' 'flood' etc -  there would be no intervention required as your email will certainly fail over as we cannot connect to you. The caveat is just point (1) and we urge it gets passed on to who is responsible in the DR situation regarding your mail server or firewall.