github-rules.sieve

if 
  allof(
  address :is "From" "notifications@github.com",
  address :is "Cc" "mention@noreply.github.com"
  )
{
  fileinto "INBOX.notifications.github.direct-mention";
}
elsif 
  allof(
  address :is "From" "notifications@github.com",
  address :is "Cc" "team_mention@noreply.github.com"
  )
{
  fileinto "INBOX.notifications.github.team-mentions";
}
elsif address :is "Cc" "your_activity@noreply.github.com" {
  addflag "\\Seen";
  fileinto "INBOX.notifications.github.my-activity";
  removeflag "\\Seen";
}
elsif 
  anyof(
  address :is "Cc" "assign@noreply.github.com",
  address :is "Cc" "review_requested@noreply.github.com"
  )
{
  fileinto "INBOX.notifications.github.assignments";
}
elsif 
  anyof(
  address :is "Cc" "comment@noreply.github.com",
  address :is "Cc" "milestone@noreply.github.com",
  address :is "Cc" "push@noreply.github.com",
  address :is "Cc" "state_change@noreply.github.com"
  )
{
  fileinto "INBOX.notifications.github.other";
}