Good sending starts with a well-structured audience. Zilch Mail supports CSV and XLSX imports, custom fields, lists, segments, deduplication, validation, and suppression management so campaign decisions can happen before a message is sent.
Prepare the import file
- Use one row per contact and include a clearly named email column.
- Keep headers unique and make field names readable, such as first_name, company, role, or source.
- Remove obvious empty rows, malformed addresses, and duplicate records before import.
- Keep dates and numeric values in consistent formats if you plan to use them in segments or templates.
- Do not import addresses that you are not legally permitted to contact.
Map fields and deduplicate
- 1Select a CSV, TXT, XLS, or XLSX file and confirm the detected email column.
- 2Map custom columns to contact fields that can be used in personalization or filtering.
- 3Review the first five preview rows for encoding, column shifts, and unexpected blank values.
- 4Deduplicate by normalized email address and resolve conflicting field values deliberately.
- 5Import into a named list that records the source and date of acquisition.
Use lists for ownership and segments for decisions
A list is a useful container for a source or business relationship. A segment is a reusable rule for deciding who should receive a specific campaign. For example, keep a list for webinar registrants, then create segments for registrants who attended, did not attend, or have a particular role.
| Segment rule | Example use | Why it helps |
|---|---|---|
| Role or title | Send a product update to operations leaders | Keeps the message relevant |
| Acquisition source | Follow up with a particular event cohort | Preserves context from the original interaction |
| Engagement event | Separate clicked contacts from non-openers | Supports different follow-up paths |
| Last contacted date | Exclude recently contacted contacts | Reduces over-mailing |
| Suppression status | Exclude unsubscribed or complained contacts | Protects compliance and sender reputation |
Treat suppression as a system-wide rule
Unsubscribes, hard bounces, complaints, and manually blocked addresses should remain excluded even when they appear in a new list. Review the suppression list before launching a campaign, and export it periodically for backup and compliance review.
Do not use a fresh import to reset an opt-out
Re-importing an address does not create permission to contact it again. An unsubscribe or complaint should remain honored across lists and campaigns.
Validate before enrolling
- Run syntax and domain checks on newly imported addresses.
- Resolve risky or disposable results according to your sending policy.
- Confirm the final recipient count after suppression and duplicate filtering.
- Send a small test to verify merge fields and segment logic before scheduling the campaign.