MergelineHow to schedule a mail merge in Gmail and set sending hours
Updated October 29, 2026
Gmail’s built-in mail merge cannot be scheduled. To send later, use a tool that starts the campaign at a set time and only sends inside the hours you choose. Mergeline Pro does both, and can send in each person’s own time zone from a TimeZone column. Your browser must be open while it sends.
Why timing matters
An email that arrives at 9am on a Tuesday sits near the top of the inbox when people sit down to work. The same email at 2am sits under a night’s worth of newsletters. For personal outreach, sending inside business hours also looks like what it is: a person writing during their day.
Sending hours also spread a big list over time. That keeps your pace human and lets you react if something goes wrong in the first hour.
What Gmail offers
Gmail’s Schedule send works for a single email. Google’s mail merge help page says mail merge cannot be combined with schedule send (Google: Send personalized emails with mail merge in Gmail). So with the built-in tool, you send the merge when you click Send, and that is it.
Some people schedule each email by hand, which works for a handful. Others write a Google Apps Script with a time trigger, which works if you can maintain it.
Scheduling versus sending hours
| Setting | What it does | Use it when |
|---|---|---|
| Start time | The campaign begins at a set date and time | You want it to land Monday morning |
| Sending hours | Emails only go out between set hours on set days | The list is bigger than one sitting |
| Recipient time zone | Hours follow each person’s local time | Your list spans countries |
| Daily cap | Stops after a set number per day | Always, to stay under Gmail’s limit |
How to schedule a campaign in Mergeline
- Build the campaign. Add your list, write the message and preview it.
- Open Review and send. This is where pacing, hours and the start time live.
- Pick a start time. Choose the date and time the campaign should begin.
- Set sending hours. Choose the days and hours, and whether they follow your time zone or each person’s.
- Set a daily cap. Pick a number below Gmail’s limit, leaving room for your normal email.
- Schedule it. Confirm. Keep the browser open at the start time, or open it later and it catches up.
Sending in each person’s time zone
Add a column named TimeZone with a standard zone name like America/New_York, Europe/London or Asia/Dubai. With sending hours on, Mergeline sends each person’s email inside the hours you chose in their local time. Rows without a zone use your own time zone.
This matters most for lists that cross oceans. A 9am send in New York is 2pm in London and evening in Dubai. With zones, each person gets the email in their morning.
The browser has to be open
Mergeline sends from your browser, not from a server, which is why your list never leaves your computer. The trade-off is that the browser must be open at send time. If it was closed, sending picks up where it left off when you open it again, still inside your sending hours.
If you need to send while your laptop is shut, leave the browser open on a desktop computer, or plan the start time for when you will be at your desk.
Good default hours
- Weekdays, 9am to 5pm in the recipient’s time zone, for work email. This is also Mergeline’s default window.
- Evenings and weekends for parents, members and volunteers, who read email outside work.
- Avoid Monday 8am and Friday afternoon for anything that needs a thoughtful answer.
- Keep the daily cap under Gmail’s limit: 500 recipients a day on a free account (Google: Gmail sending limits).
Example schedules
| Goal | Start | Sending hours | Daily cap |
|---|---|---|---|
| Client update, one city | Tuesday 9am | Weekdays 9am to 5pm, your time | 200 |
| Sales outreach, many countries | Monday 8am | Weekdays 9am to 11am, their time | 50 |
| Volunteer reminders | Thursday 6pm | Every day 6pm to 9pm | 100 |
| Parent emails | Sunday 7pm | Sunday to Thursday 6pm to 8pm | 60 |
These are examples to adapt, not rules. The pattern is the same each time: pick the hours your readers check email, pick a cap well under your limit, and let the campaign run across several days if it needs to.
Questions
Can I pause a scheduled campaign?
Yes. Pause it at any time, and resume when you are ready. Emails that were not sent yet wait, and the daily cap still applies when you resume.
What happens if my laptop sleeps during sending?
Sending pauses while the browser is not running and resumes when it wakes, as long as it is still inside your sending hours.
Can I send only on weekdays?
Yes. Sending hours let you pick the days of the week as well as the hours.
What time zone names work?
Standard names like America/Chicago, Europe/Paris or Australia/Sydney. Rows with an empty or unknown zone use your own time zone.
Can I schedule a mail merge in Gmail?
Not with Gmail’s built-in mail merge. Google says it cannot be combined with schedule send. Use a tool with scheduling, such as Mergeline Pro.
Does my computer need to be on?
For Mergeline, yes: the browser must be open. If it is closed, sending resumes when you open it.
How do I send in each recipient’s time zone?
Add a TimeZone column with zone names like America/New_York and turn on sending hours.
Do follow-ups respect sending hours?
Yes. Follow-ups wait for the next allowed hour, like first emails.
Is scheduling free?
Scheduling and sending hours are part of Pro. Pro is $12 a month or $99 a year.
Sources
Facts checked October 29, 2026. Google and other vendors change their limits and prices, so check the source before you rely on a number.
Mergeline does this from your own Gmail. Free for 60 emails a day with merge tags and no branding. Pro is $12 a month or $99 a year for follow-ups, scheduling and attachments.