A mail merge goes wrong at the data, not at the letter. Fix the spreadsheet, write the letter once, and preview before you merge.
Take a community garden club sending 180 renewal letters. The list lives in a spreadsheet someone has added to for six years. Some people are in as “SMITH, jan”, some have no first name at all, and two have a postcode in the suburb column.
Each of those becomes a visible mistake on a printed page. The merge engine fills in exactly what is in the cell, so “Dear SMITH, jan” is what you get. Give every fact its own column with a plain header (FirstName, LastName, Street, Suburb, Postcode, MembershipType, Amount, RenewalDate), and decide now what a blank means.
Postcodes need one specific check. Excel treats a postcode like a number and drops the leading zero, so 0800 becomes 800. Microsoft’s support page on preparing an Excel data source says leading zeros are dropped during a Word mail merge if the column is not formatted as text. Oppermind is not affiliated with, endorsed by, or sponsored by Microsoft. If you export a CSV from Excel after the zero has gone, the CSV has lost it for good.
Oppermind’s side of this is simple. Whatever text you paste is what gets merged, and nothing converts a value to a number or a date. A postcode that is 0800 in the CSV text is 0800 on the page.
Open a Document, or ask Lato to draft the letter and tell it which fields you have. Something like “write a friendly renewal letter for a gardening club, with {{FirstName}}, {{MembershipType}}, {{Amount}} and {{RenewalDate}} as fields, under 200 words”. The editor understands two kinds of field. One is a double-brace token typed into the text. The other is a merge field you place from the Insert menu, which shows as a purple «FirstName» chip you can click around without breaking.
The chip is worth using in a letter you will keep editing. When you ask the AI to rewrite a paragraph, the rewrite step leaves merge-field chips alone, so «FirstName» survives a request to make the tone warmer. Plain tokens are text, so check them after any rewrite.
Write each sentence with your messiest row in mind. If Amount is sometimes blank, the sentence “Your renewal is {{Amount}}” will print as “Your renewal is .” for those people. Rephrase so the field sits in a place where an empty value reads as a gap you will catch in the preview, or fix those rows in the data.
Choose Mail merge from the Tools menu, then paste the data. The first row is read as column names. Commas, tabs, semicolons and pipes are detected, and quoted cells with commas or line breaks inside them are handled, which matters for an address typed over two lines.
A status line then reports the number of records and how many fields matched. Any field in the letter with no matching column is listed in red by name. That catches the common slip where the sheet says “First Name” and the letter says «FirstName».
Preview first opens a page-sized view of record 1 with Previous and Next buttons, labelled as a preview only. Your document is unchanged while you look. Check the first row, the last row, and the strangest one you can find, such as the longest street name or the person with two surnames.
Merge all replaces the template with one document containing every record, a page break between them. The toast says how many records were merged and that Undo puts the template back. Keep a copy of the template before you save anything you want to reuse, because the merged version is a different document.
From there you print it or use Export PDF or Export Doc, and you get one file containing all 180 letters. There is no option to write one file per recipient, and nothing here posts or emails anything. Values from your data are inserted as plain text, so a cell containing angle brackets prints as those characters and is not read as formatting.
Two smaller controls exist in the engine but have no menu behind them yet. A field can carry a default for blank cells, and a format of upper, lower, title or trim. Today those only work in the document’s HTML, so a blank cell is best fixed in the data.
| Job | Where | What Oppermind does today |
|---|---|---|
| Printed letters, certificates, notices | Document, Tools, Mail merge | One merged document, a page per record, print or PDF. |
| A few personal emails | Email editor | Composes and sends one message at a time (To, Cc, Bcc) from a connected account. No merge from a data file. |
| Bulk marketing email | Not in Oppermind | Use a dedicated email service that manages consent and unsubscribes. |
| Address labels | Not built | Merge output is a page per record, not a label sheet. |
If you want personal emails to ten people with different details, the practical route is to merge the letter, then use the Email editor for each one, or ask Lato to draft each message from a row you paste. Ten of those are manageable, and a hundred would mean a lot of copying.
What Oppermind does with the data is one question, and what you are allowed to do with the list is another. On the first, the merge runs inside the editor on the text you paste, and the merge code makes no network calls. Once you merge, though, the names and addresses are part of the document, so they are handled like anything else in your documents. If you also paste the list into a chat with Lato, that text goes to the assistant, so a sensible habit is to give the assistant the letter and one invented row, then paste the real list only into the merge dialog. The privacy and data guide covers how your content is handled.
The second question sits with you.
For email, Australia’s Spam Act 2003 has separate sections on three things: unsolicited commercial electronic messages must not be sent, they must include accurate sender information, and they must contain a functional unsubscribe facility. General information, not legal advice.
Paper mail has its own rule. The Office of the Australian Information Commissioner says the direct marketing principle (APP 7) generally applies to mail sent by post or hand delivered, and that an organisation must give a simple way to opt out of future direct marketing. General information, not legal advice. The Privacy Act’s reach depends on who you are. The OAIC guidance describes it as applying to private sector organisations with annual turnover above A$3 million and to some smaller ones, so check your own position with the OAIC or an adviser before a large send.
A renewal letter to your own members is a different thing from a mailout to a bought list. Keep the opt-out column in the spreadsheet and drop those rows before you paste.
The dialog takes pasted text, so copy the cells and paste. Tab-separated text is read the same way as CSV.
No. A test checks that it never writes into the document.
The second becomes Header_2, and a blank header becomes Column and its position, so nothing is silently overwritten.
Try the merge on a 5-row list and a one-paragraph letter. Free needs no card. Paid plans are Starter A$9.95, Pro A$29.99 and Pro Plus A$59.99 per month, subject to plan terms.
Try the merge on a short list and a one-paragraph letter, in a workspace with documents, sheets and decks.