Getting Tellmerge working.

Almost always the page failing to load rather than the add-in failing to run. Close the pane and reopen it; if it is still blank, check that tellmerge.com loads in a normal browser tab from the same machine. Corporate networks sometimes block unfamiliar domains, and the add-in cannot tell you that from inside a blank frame.

If your organisation filters by domain, ask IT to allow tellmerge.com.

Reopen the add-ins dialog and confirm Tellmerge is listed — under My add-ins if you installed it from AppSource, or Custom Addins if you added the manifest. Outlook occasionally needs a page refresh before a freshly added add-in shows up. On a narrow window the ribbon collapses, so check under Apps or … before concluding it is missing.

Also worth knowing: if you install a newer manifest without removing the old one first, Outlook keeps the old one. Remove, then add.

Tellmerge matches the filename in your sheet against the files you picked. It ignores case and any folder path in the cell, and will fall back to matching on the name without its extension — but it will not guess. Two common causes:

The file genuinely isn't in the folder you chose (a typo in the sheet, or the file lives elsewhere), or two of your files share a name apart from the extension, so Tellmerge refuses to pick one. Fix the sheet or narrow the folder selection.

A row with a missing attachment is deliberately not sent. An invoice email with no invoice attached is worse than no email at all. It is listed on the send report as Not sent, with the row number and the reason, so the record of a run accounts for everybody on your list and not only the ones who received something.

Save it as a template. A template keeps the subject, the message and which columns your fields point at — so next month you drop in the new spreadsheet and the wording is already there. It does not keep your recipient list or your files; those come from the sheet and the folder you pick each time.

Templates are stored against your mailbox rather than the machine, so one saved at your desk is there on your laptop.

Yes. Write it once in the Signature section and it is appended below every merged message, after a blank line. It travels with your mailbox in the same way templates do.

It can carry merge fields of its own, so a sign-off naming the account manager for each row works exactly as the body does.

No. The summary screen offers to retry only the ones that failed, and the count afterwards reflects the whole run rather than just the retry. Nobody who received their email the first time gets a second copy.

If the connection dropped mid-send, anything Tellmerge could not get an answer about is listed separately as not confirmed rather than as a failure, and is deliberately left out of the retry. Those may already have arrived, and sending a customer a second invoice is worse than asking you to check your Sent Items for a handful of rows.

Every run produces a report you can download as a CSV: each recipient, what happened, which file their email carried, and the time it went, in UTC. Rows that were held back appear too, marked Not sent with the reason. Open it in Excel and keep it with the month’s paperwork.

“Did the March payslips actually go out?” is a question people have to answer to someone else, sometimes months later, and reconstructing it from a Sent Items folder is nobody’s idea of an afternoon. If a download is awkward on your version of Outlook, the same report copies to the clipboard and pastes straight into a spreadsheet.

Add a Cc or Bcc column to your sheet and point Tellmerge at it. Each row can copy different people — an account manager, a branch office, your own records.

A copy is never allowed to cost someone their document: if an address in a Cc cell is unusable, that address is named for you while the spreadsheet is still open and the row still sends. Nobody is copied on their own email, and anyone already copied openly is not copied again invisibly.

For a cell that may be blank, write {{First|there}} — the part after the bar is used when the cell is empty, so the greeting reads “Hi there,” instead of trailing off.

For money and dates, ask for the shape you want: {{Amount:amount}} gives 1,250.50 and {{Due:date}} writes the date out in full rather than leaving 09/06/2026 to be read two different ways on two sides of an ocean. For the Bahraini dinar and the other three-decimal currencies — KWD, OMR, JOD, TND — {{Amount:amount3}} gives 12.345, which two decimal places would quietly round away.

Microsoft limits how fast and how much a single mailbox may send, and the limit differs by account type. When it pushes back, Tellmerge slows down and retries rather than hammering through — which is what protects your account from being flagged.

Throttled recipients are retried automatically and counted for you on the summary screen. If a very large batch keeps stalling, split it across two days.

Tellmerge decides how to read a file by looking at its contents, not its extension, so this is rare. If it happens, the file is usually not what its name suggests — a .csv that is really an Excel workbook, or a file saved in an unusual encoding. Open it in Excel and re-save as .xlsx.

Open Tellmerge in the mailbox that currently holds the seat and choose Deactivate. The seat frees immediately and the key can be entered elsewhere.

If you can no longer open that mailbox — someone left the company, an account was closed — email [email protected] with your order number and we will release it for you.

The trial lasts 14 days from the first time you open Tellmerge in a mailbox. After that sending stops until a key is entered — but nothing is deleted, the add-in stays installed, and your lists were never ours to hold. Enter a key and you carry straight on.

Email [email protected]. Tell us which Outlook you use (web, Windows, Mac), whether the mailbox is Microsoft 365 or Outlook.com, and what you saw. A screenshot of the pane usually saves a round trip.

Please don't send us your recipient list or your attachments — we don't want them and we don't need them to help.