

Every agency owner and marketer eventually hits the same wall: your list lives in Google Sheets, your conversations live in Gmail, and your time disappears somewhere in between.Manually copying rows, personalizing subject lines, and tracking who replied works when you have 20 leads. At 2,000, it becomes a second job. Google’s own mail merge examples show how powerful it is to merge spreadsheet columns into Gmail templates with Apps Script. Your sheet already knows who should get what message and when. Turning that into an automated pipeline means fewer missed follow-ups, faster campaigns, and a single source of truth for your team.This is where an AI agent changes the story. Instead of you pressing “Run” on scripts, an AI computer agent watches Google Sheets, opens Gmail, updates templates, sends messages, and logs status like a tireless SDR. Delegating this work to an AI agent means campaigns go out on time, errors get caught, and you stay in the strategic role—deciding the offer and the audience, not fighting with filters and formulas.
If you run a business, agency, or sales team, email is where revenue actually happens. Google Sheets holds your lists; Gmail holds your conversations. The question is how to connect them in a way that doesn’t eat your entire week.Below are three levels of Google Sheets → Gmail automation: from simple, to no‑code, to fully delegated with an AI agent.### 1. Manual & Script-Based Methods (3 Ways)#### 1.1 Copy‑Paste + Gmail Templates (baseline)This isn’t true automation, but it’s your control example.**Steps:**1. In Gmail, turn on templates: go to **Settings → See all settings → Advanced**, enable **Templates**, then **Save changes**. - Docs: https://support.google.com/mail/answer/92167262. Compose an email, insert placeholders like `{{First name}}`, then save it as a template.3. In Google Sheets, keep columns such as `First name`, `Email`, `Offer`.4. Filter a small segment, then manually copy the email address and personalize the template before sending.**Pros:** Full control; great for testing messaging.**Cons:** Completely manual; doesn’t scale beyond a few dozen emails.#### 1.2 Apps Script Mail Merge from GoogleGoogle publishes an official sample that merges data from Sheets into a Gmail draft.**Steps (high level):**1. Open Google’s sample mail merge spreadsheet and copy it: - https://developers.google.com/apps-script/samples/automations/mail-merge2. In the copied Sheet, replace sample data with your own. Make sure you keep a `Recipient` column and an `Email Sent` column.3. In Gmail, create a draft email. Use placeholders matching your column headers, such as `{{First name}}`, `{{Company}}`.4. Back in Sheets, refresh and you’ll see a **Mail Merge** menu. Click **Mail Merge → Send Emails**.5. Paste the exact Gmail subject line of your draft when prompted, approve permissions, then run again.**Pros:** Free, native, and documented by Google. Personalization at scale.**Cons:** Requires light scripting knowledge if you want to customize; bound by Gmail quotas:- Quotas: https://developers.google.com/apps-script/guides/services/quotas#### 1.3 Time‑Driven Apps Script TriggersOnce your basic mail merge works, you can have it run automatically on a schedule.**Steps:**1. Open **Extensions → Apps Script** from your Sheet.2. In the script editor, use Google’s sample `sendEmails()` function or your own.3. Click the clock icon (**Triggers**) in the left sidebar.4. Add a new trigger: - Choose function: `sendEmails` - Event source: **Time‑driven** - Select an interval (e.g., every hour or once a day) - Save and grant permissions.5. Mark rows as sent (e.g., via the `Email Sent` column) so the script skips them next run.**Pros:** Fully unattended; good for drip sequences and daily sends.**Cons:** Debugging requires reading logs in Apps Script; non‑technical users may get stuck.Helpful references:- Apps Script & Sheets: https://developers.google.com/apps-script/guides/sheets- Gmail service: https://developers.google.com/apps-script/reference/gmail/gmail-app### 2. No‑Code Methods with Automation ToolsIf you don’t want to touch code, add‑ons and workflow tools sit nicely between Sheets and Gmail.#### 2.1 Sheet Automation Add‑onSheet Automation (Workspace Marketplace) lets you trigger emails when rows change—no scripts.**Steps:**1. Install from the Marketplace: https://workspace.google.com/marketplace (search for **Sheet Automation - Automate Google Sheets**).2. Open your Sheet, go to **Extensions → Sheet Automation**.3. Create a new rule: - Trigger: when a row is added or updated. - Condition: e.g., `Status = "Ready to email"`. - Action: **Send email**.4. Map columns to email fields: `Recipient` → To, `Subject` → Subject, `Body` or template variables.5. Test with one row, then turn the rule on.**Pros:** True no‑code; point‑and‑click configuration; supports schedules and conditions.**Cons:** Complex logic can become hard to manage; you’re still responsible for design, lists, and throttling.#### 2.2 Third‑Party No‑Code Platforms (Zapier/Make)While not strictly Google tools, they sit on top of Google’s APIs.**Typical flow:**1. **Trigger:** "New or updated row" in Google Sheets.2. **Filter:** Only continue if `Status = Send`.3. **Action:** Send email via Gmail connector.You still design the Sheet schema and email copy; the tool handles the wiring.**Pros:** Very flexible; easy branching and multi‑step workflows.**Cons:** Per‑task pricing; API‑level issues or quota errors can break flows without you noticing.Official Sheets API docs (for background):- https://developers.google.com/sheets/api### 3. AI Agent–Driven Automation at Scale (with Simular)Traditional and no‑code methods are great, but they all assume **you** are the operator: tweaking scripts, fixing broken add‑ons, and babysitting triggers. An AI computer agent changes that by acting like a smart teammate who can literally use your desktop, browser, Google Sheets, and Gmail for you.Simular Pro is built exactly for this: autonomous computer use agents that can run thousands to millions of steps with production‑grade reliability.#### 3.1 Simular Agent Running Your Mail Merge End‑to‑End**What it looks like in practice:**- You maintain a Google Sheet with `First name`, `Email`, `Offer`, `Status`.- You keep a Gmail draft template.- A Simular agent is instructed to: 1. Open your browser and navigate to the Sheet. 2. Filter rows where `Status = "Ready"` and email not yet sent. 3. For each row, open Gmail, duplicate the draft, fill in personalized fields, and send. 4. Write back `Sent` and a timestamp into the Sheet.Because Simular Pro works across the entire desktop environment, the workflow is transparent: every click and keystroke is logged and inspectable.**Pros:**- Behaves like a trained human assistant; no API plumbing.- Handles long, multi‑app workflows (Sheets → CRM → Gmail → Docs).- Transparent execution; easy to audit.**Cons:**- Requires an initial onboarding: you show the agent how your process works.- Best suited for teams ready to standardize their workflows.Learn more: https://www.simular.ai/simular-pro#### 3.2 Event‑Driven Campaigns with Simular + WebhooksBecause Simular Pro supports webhooks, you can trigger an AI agent when a specific event happens—say, a row is added to your "New Leads" Sheet.**Example flow:**1. A form or CRM integration writes a new lead into Google Sheets.2. A webhook notifies Simular: "Run the lead‑welcome workflow".3. The Simular agent: - Opens the Sheet, enriches data from the web (e.g., LinkedIn or company site). - Writes enriched fields back into the Sheet. - Opens Gmail, crafts a hyper‑personalized first‑touch email. - Logs the outcome plus notes (e.g., "found CTO contact") in the Sheet.**Pros:**- Real "set‑and‑forget" campaigns; the AI runs continuously.- Can combine research, copywriting, and sending in one flow.**Cons:**- You must define clear guardrails: max emails per day, allowed domains, etc.By layering an AI agent like Simular on top of your existing Google Sheets and Gmail setup, you move from "I run an automation" to "I manage a digital SDR team"—without adding headcount.
If you’re just getting started, the easiest path is Google’s own mail merge sample. It uses Apps Script but requires almost no coding.1) Open Google’s sample: go to https://developers.google.com/apps-script/samples/automations/mail-merge and click the link to **Make a copy** of the sample spreadsheet.2) In the copied Sheet, replace the demo contacts with your leads. Keep the `Recipient` and `Email Sent` column names, or update the constants `RECIPIENT_COL` and `EMAIL_SENT_COL` in the script.3) In Gmail, create a draft email with placeholders like `{{First name}}` that exactly match your Sheet headers. Copy the subject line.4) Back in Sheets, refresh the page. Use the new **Mail Merge** menu → **Send Emails**, paste your draft’s subject, and authorize the script.5) Run **Send Emails** again. The script fills placeholders from each row and sends from your Gmail account.This approach gives you native personalization, logging, and a simple UI, perfect for small campaigns.
To personalize Gmail messages with Google Sheets data, you map column headers to placeholder tags in a Gmail draft.1) Design your Sheet with clear headers: `First name`, `Company`, `Pain point`, `Offer`, `Recipient`.2) In Gmail, write a draft such as: "Hi {{First name}}, I saw {{Company}} is working on {{Pain point}}…". The double curly braces will be replaced by Apps Script.3) Use Google’s mail merge example or your own Apps Script. In either case, the script loads your Sheet with `getDisplayValues()`, treats the first row as headers, and builds an object for each row like `{ 'First name': 'Ana', 'Company': 'Acme' }`.4) The helper function replaces every `{{Header}}` in your Gmail draft body and subject with the corresponding value from the row.Because the emails are sent from your Gmail account, replies land in your normal inbox, and every message can still feel handcrafted even though the personalization comes directly from sheet data.
To send daily emails automatically from a Sheet, you combine mail merge logic with a time‑driven trigger in Apps Script.1) Start from the official mail merge sample (or your own `sendEmails()` function) attached to your Sheet. Open **Extensions → Apps Script** to see the code.2) Ensure your script only emails rows that haven’t been processed. The sample uses an `Email Sent` column—if that cell is blank, it sends; after sending, it writes a timestamp.3) In the Apps Script editor, click the clock icon (**Triggers**). Add a new trigger for `sendEmails`.4) Choose **Time‑driven** as the event source, and set the schedule: for example, **Day timer** → between 8am and 9am.5) Save and grant permissions. From now on, Apps Script will run `sendEmails()` daily, scanning the Sheet for new unsent rows and sending them automatically.Monitor quotas (https://developers.google.com/apps-script/guides/services/quotas) to stay within Gmail daily limits, and always test with a small list first.
Google enforces daily sending limits, especially on standard Gmail accounts, so you must design your Sheet‑driven campaigns with quotas in mind.1) Check current limits here: https://developers.google.com/apps-script/guides/services/quotas. For many accounts, you’re looking at 100–1500 recipients per day depending on your plan.2) Add controls to your Sheet: include a `Send batch` column or date column. Your script should only process a certain number of rows per run.3) In `sendEmails()`, maintain a counter and stop once you hit your daily cap. That way, you never trigger a hard block.4) Stagger campaigns using time‑driven triggers (e.g., multiple small runs per day) instead of one big blast.5) For higher volume, offload part of the work to an AI agent like Simular: it can segment leads, warm up inboxes, and schedule sends over multiple days, while you stay safely within Gmail’s thresholds.This approach keeps deliverability healthy and avoids sudden service interruptions.
You should consider moving from simple Apps Script automations to an AI computer agent when managing the workflow becomes more work than sending the emails.Warning signs:- You maintain multiple scripts across several Sheets and brands.- Non‑technical teammates constantly ask you to debug or "just tweak one thing".- Your process spans tools: Sheets → CRM → LinkedIn research → Gmail → logging notes.An AI agent platform like Simular Pro can operate your desktop, browser, Google Sheets, and Gmail like a trained assistant. Instead of stitching APIs, you teach it the workflow once: open this Sheet, filter these leads, research context, draft a tailored message, send from Gmail, then log outcomes.You still define strategy—who to target, what to say, what success looks like. The agent handles execution at scale, with transparent logs and production‑grade reliability. That’s when AI stops being a gadget and becomes real leverage for your sales or marketing team.