When sending out most email Launchpad will include X-Launchpad-Message-Rationale and X-Launchpad-Notification-Type headers which you can filter with.

In all cases where it includes X-Launchpad-Message-Rationale for a notification directed at a person or a team, Launchpad will also include an X-Launchpad-Message-For header identifying the person or team that the notification is for: for example, if your username is `some-user` and you are subscribed directly to a bug, then the notification will have `X-Launchpad-Message-For: some-user`, while if you are a member of `ubuntumembers` and you receive bug mail because that team is subscribed to a bug, then the notification will have `X-Launchpad-Message-For: ubuntumembers`.

= Bugmail =

The basic rationale headers are for the cases where you are directly related to a bug:

{{{
    X-Launchpad-Message-Rationale: Assignee
    X-Launchpad-Message-Rationale: Subscriber
}}}

If you are related to a bug through a team, an @ notation is added:

{{{
    X-Launchpad-Message-Rationale: Assignee @ubuntu-kernel-bugs
    X-Launchpad-Message-Rationale: Subscriber @ubuntu-core-dev
}}}

Bug Contacts and Registrants, which are implicitly subscribed to public bugs, have their own headers:

{{{
    X-Launchpad-Message-Rationale: Bug Contact (mozilla-firefox in ubuntu)
    X-Launchpad-Message-Rationale: Registrant (kiwi)
}}}

This is combined with the @ notation when you are a member of a team who is bug contact:

{{{
    X-Launchpad-Message-Rationale: Bug Contact (ubuntu) @ubuntu-bugs
}}}

If the notification was generated in a duplicate bug, we tack on a via string:

{{{
    X-Launchpad-Message-Rationale: Assignee via Bug 1332
}}}

This one is worth explaining a bit further. Let's say this bugmail is for bug 2129; the header here means you are the assignee of "master bug" 1332, of which 2129 is a duplicate. You can use this header to filter away bug that you are receiving from duplicates of a bug you are subscribed to.

All bugmail also has:

{{{
    X-Launchpad-Notification-Type: bug
}}}

= Answer Tracker Mail =

The basic rationale headers are for the cases where you are directly related to a question:

{{{
    X-Launchpad-Message-Rationale: Assignee
    X-Launchpad-Message-Rationale: Subscriber
}}}

The other possibility is when you are receiving the notification because you are an answer contact 
for the question's target:

{{{
    X-Launchpad-Message-Rationale: Answer Contact (mozilla-firefox in ubuntu)
    X-Launchpad-Message-Rationale: Answer Contact (Ubuntu)
}}}

This is combined with the @ notation when you are a member of a team who is an answer contact:

{{{
    X-Launchpad-Message-Rationale: Answer Contact (Launchpad) @launchpad-qa
}}}

= Code Hosting Mail =

Mail is only sent to subscribers of branches.  If you are directly subscribed to a branch the rationale header is:

{{{
    X-Launchpad-Message-Rationale: Subscriber
}}}

This is combined with the @ notation when you are a member of a team who is subscribed to the branch:

{{{
    X-Launchpad-Message-Rationale: Subscriber @ubuntu-core-dev
}}}

There are various notification types for code.  When the properties of a branch are modified (for example using "Change details"):

{{{
    X-Launchpad-Notification-Type: branch-updated
}}}

When new revisions are found on a branch:

{{{
    X-Launchpad-Notification-Type: branch-revision
}}}

For notifications related to merge proposals:

{{{
    X-Launchpad-Notification-Type: code-review
}}}

= Build Mail =

Notifications regarding the various types of builds that Launchpad can perform for you have associated rationales.  If you requested a source package recipe, [[LiveFilesystem|live filesystem]], or snap package build:

{{{
    X-Launchpad-Message-Rationale: Requester
}}}

If you created the source package (you are listed in its `Changed-By` field for a direct upload, or you requested a copy):

{{{
    X-Launchpad-Message-Rationale: Creator
}}}

If you did not create the source package but you signed it:

{{{
    X-Launchpad-Message-Rationale: Signer
}}}

If you did not create or sign the source package, but the build is in a PPA that you own:

{{{
    X-Launchpad-Message-Rationale: Owner
}}}

Any of these may have the @ notation appended if the relation is through a team, as above.

The notification type indicates which kind of build prompted the notification.  It will be one of:

{{{
    X-Launchpad-Notification-Type: package-build-status
    X-Launchpad-Notification-Type: recipe-build-status
    X-Launchpad-Notification-Type: livefs-build-status
    X-Launchpad-Notification-Type: snap-build-status
}}}

= Upload Mail =

Launchpad sends notifications in response to source package uploads.  If you signed a source package or requested a copy (these may be separated into distinct rationales in future):

{{{
    X-Launchpad-Message-Rationale: Requester
}}}

For primary archives, if you did not sign the source package or request the copy, but you are listed in its `Maintainer` field:

{{{
    X-Launchpad-Message-Rationale: Maintainer
}}}

For primary archives, if you did not sign the source package or request the copy and are not listed in its `Maintainer` field, but are listed in its `Changed-By` field:

{{{
    X-Launchpad-Message-Rationale: Changed-By
}}}

For PPAs, if you did not sign the source package or request the copy, but you have been manually configured as an additional uploader to the PPA (this is an unusual configuration):

{{{
    X-Launchpad-Message-Rationale: PPA-Uploader
}}}

Any of these may have the @ notation appended if the relation is through a team, as above.

Most package uploads to primary archives also cause an announcement to the appropriate -changes mailing list.  This has:

{{{
    X-Launchpad-Message-Rationale: Announcement
}}}

All package upload mail also has:

{{{
    X-Launchpad-Notification-Type: package-upload
}}}

= Team Membership Mail =

Launchpad sends notifications of team membership changes.  For an invitation to a team you administer to join another team:

{{{
    X-Launchpad-Message-Rationale: Invitation (target-team-name) @name-of-team-you-administer
    X-Launchpad-Notification-Type: team-membership-invitation
}}}

For all other team membership notifications, the rationale depends on your relationship to the team containing the membership:

{{{
    X-Launchpad-Message-Rationale: Member (team-name)
    X-Launchpad-Message-Rationale: Admin (team-name)
    X-Launchpad-Message-Rationale: Owner (team-name)
}}}

Your relationship to the team containing the membership may be by way of another team.  For instance, if you are a member of `project-leader`, and `project-leader` is the owner of `project-dev`, then a notification that a new member has been added to `project-dev` would have this rationale:

{{{
    X-Launchpad-Message-Rationale: Owner (project-dev) @project-leader
}}}

In each case, the notification type describes the event that caused the notification, which may be a new member joining a team, a pending new membership that needs approval, a changed membership status, an expired membership, an accepted invitation to join a team, a declined invitation to join a team, a membership that will expire soon, or a member extending the term of their own membership:

{{{
    X-Launchpad-Notification-Type: team-membership-new
    X-Launchpad-Notification-Type: team-membership-pending
    X-Launchpad-Notification-Type: team-membership-change
    X-Launchpad-Notification-Type: team-membership-expired
    X-Launchpad-Notification-Type: team-membership-invitation-accepted
    X-Launchpad-Notification-Type: team-membership-invitation-declined
    X-Launchpad-Notification-Type: team-membership-expiration-warning
    X-Launchpad-Notification-Type: team-membership-renewed
}}}