Steps to reproduce:

• have multiple hosts with its items and triggers (all based on templates):

  Number of hosts (enabled/disabled/templates)	203	102 / 1 / 100
  Number of items (enabled/disabled/not supported)	21703	19959 / 1392 / 352
  Number of triggers (enabled/disabled [problem/ok])	3771	3441 / 330 [35 / 3406]
  

• put some hosts in Maintenance via Configuration -> Maintenance
• enable the subject alerts via Configuration -> Actions
• send the hosts in Maintenance to reboot

Result:

1. received many emails (1100+) about falling to "Not supported" and back to "Normal" states
2. no single email about non-reachability, not running service, etc. I.e. not via normal trigger

Expected:

• under #1, excepted no such emails
• #2 - behaviour as expected.