Bulk Migration CSV Format
This guide explains CSV format specification for bulk email migration with examples and templates. so you can complete the TrekMail task with confidence.
Article details
Type, difficulty, plans, and last updated info.
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Article details
Type, difficulty, plans, and last updated info.
- Type
- Guide
- Difficulty
- Intermediate
- Plans
- Starter · Pro · Agency
- Last updated
- Apr 29, 2026
This page describes the CSV format used by the Bulk Import tool.
Simple format (3 columns)
Use this when all source accounts are on the same provider (e.g., all Gmail). Set the provider in the form — server details are auto-filled.
source_email,source_password,destination_email
alice@gmail.com,abcd-efgh-ijkl-mnop,alice@yourdomain.com
bob@gmail.com,qrst-uvwx-yz12-3456,bob@yourdomain.com
carol@gmail.com,7890-abcd-efgh-ijkl,carol@yourdomain.com
| Column | Description |
|---|---|
source_email |
The email address on the old provider. |
source_password |
The IMAP password or App Password for the source account. |
destination_email |
The TrekMail mailbox to import into. Must already exist in your account. |
No destination password needed. TrekMail authenticates to your mailboxes automatically.
Full format (6 columns)
Use this when source accounts are on different providers. Check Each row has its own server settings in the form.
source_email,source_password,destination_email,source_host,source_port,source_security
alice@gmail.com,app-pw-1,alice@yourdomain.com,imap.gmail.com,993,ssl
bob@outlook.com,app-pw-2,bob@yourdomain.com,outlook.office365.com,993,ssl
carol@oldhost.com,pw-3,carol@yourdomain.com,mail.oldhost.com,993,ssl
| Column | Description |
|---|---|
source_email |
Source email address. |
source_password |
Source IMAP password or App Password. |
destination_email |
TrekMail mailbox (must exist in your account). |
source_host |
IMAP server hostname of the source provider. |
source_port |
IMAP port (usually 993 for SSL). |
source_security |
ssl, tls, or none. |
Downloadable templates
- Simple template (3 columns) — one example row included.
- Full template (6 columns) — one example row included.
Rules
| Rule | Details |
|---|---|
| Max file size | 2 MB |
| Encoding | UTF-8 (files in other encodings are rejected) |
| Max rows | Depends on plan: 100 (Starter), 300 (Pro), 1,000 (Agency) |
| Header row | Optional. Auto-detected if first row contains column names. |
| Delimiters | Comma ,, tab, or semicolon ; (auto-detected). |
| Empty lines | Skipped. |
| Comments | Lines starting with # are skipped. |
| Emails | Lowercased and trimmed automatically. |
| Passwords with commas | Wrap in double quotes: "pass,word" |
| Passwords with quotes | Escape with double quotes: "pass""word" |
Common mistakes
- Using regular password instead of App Password. Gmail, Yahoo, and iCloud require App Passwords for IMAP access. See Migrate from Gmail.
- Destination mailbox doesn't exist. Create mailboxes in TrekMail first, then run bulk import.
- Wrong number of columns. Simple mode expects 3 columns; full mode expects 6. Extra columns are ignored in simple mode.
- Non-UTF-8 file. Save your CSV as UTF-8 in your spreadsheet application.
Related articles
Jump to nearby guides that continue the workflow.