id | mail            | service (comma separated)
-----------------------------------------------
1  | name1@gmail.com | TV, Internet
2  | name2@gmail.com | Cloud, Internet
3  | name3@gmail.com | Phone, Cloud

id | title      | message               | service (comma separated)
------------------------------------------------------
1  | Disruption | TV services offline   | TV
2  | Maintenace | All services offline  | TV, Internet, Cloud
3  | Disruption | Some services offline | TV, Internet

sub_id | mail
-----------------------------------------------
1      | name1@gmail.com
2      | name2@gmail.com
3      | name3@gmail.com

message_id | title   | text
-----------------------------------------------
1          | Disruption | ...
2          | Maintenace | All services offline
3          | Disruption | Some services offline

service_id | title
-----------------------------------------------
1          | TV
2          | Internet
3          | Phone

sub_id | service_id
---------------------
1       | 1
1       | 2

message_id | service_id
---------------------
1          | 1
1          | 2