What you can filter on
Standard fields
Name, email, phone, identifier, country, city, created date, last activity, company, blocked status.
Labels
Whatever tags you’ve applied to contacts — the one filter type that isn’t a plain field on the contact itself.
Managing a segment
A saved segment is a name and a query — nothing else is frozen at save time. Editing one changes what it returns going forward; you’re not creating a new version alongside the old one. Deleting it just removes the saved shortcut — it was never the only way to reach those contacts, since the same filter can always be rebuilt from scratch on the contacts list.Segments are one of three filter types
The same saved-filter mechanism backs three different things: filters on contacts, filters on conversations, and filters used for reporting. “Segment” is specifically the contacts one — the dashboard’s name for a contact filter you’ve chosen to save. A saved conversation filter is the same underlying idea, covered under custom views instead.A segment is scoped to the person who created it. It isn’t shared with the rest of your team by default the way a label is — if a segment needs to be a team-wide reference point, coordinate on the filter criteria directly rather than assuming everyone sees your saved list.
Segments and campaigns
A one-off campaign needs an audience, and the mechanism it actually uses is labels, not a saved segment directly — a campaign selects everyone carrying a chosen label, computed at send time. If you’ve built a segment filtered on a label, that segment and a campaign aimed at the same label describe the same group of people, but saving a segment doesn’t, by itself, hand that audience to a campaign. Build the grouping around a label if the plan is to eventually message it. See Campaigns.Next
Attributes and custom fields
What a segment can filter on, in more depth.
Importing contacts
Getting the underlying data into shape before you filter it.
Campaigns
Where label-based audiences actually get used.
Labels
The tagging mechanism campaigns target directly.