1. In the web console, under the Settings section, you will find a link for 'Initial Alerting Setup' where you can specify global defaults. On the SolarWinds server, open the Advanced Alert Manager and look at the email trigger action for the 'alert me when a node is down' and you will find how the email to/from/SMTP server specified in the initial alerting setup are referenced as variables
2. You can use the unmanage scheduling utility on the Solarwinds server to unmanage an application monitor on a scheduled basis. It is not possible to unmanage a specific component monitor (open feature request for which you can vote on https://thwack.solarwinds.com/ideas/1011). The workaround would to be create an application template with just 1 component monitor for this service that has a regular scheduled maintenance. Another dirty workaround is to create an Outlook rule (assuming you use Exchange) that runs on the server to move to a folder, so that it doesn't pop up on your smartphone