Gmail is the email at the heart of Google Workspace. Google calls it the most used email in the world, and on Workspace it gives each person a professional address on the business’s own domain, with up to 30 aliases each.
Google says Gmail blocks 99.9% of spam automatically, phishing and malware included.
Working as a team
Labels and filters sort mail as it arrives, archiving or forwarding it automatically. Delegation lets an assistant read and send from someone else’s inbox, and a Google Group can work as a collaborative inbox, where conversations are assigned to people and marked complete.
Gemini in Gmail summarizes long threads and drafts replies on eligible plans, and since September 2026 Gmail search can give AI overviews of what it finds. Claude’s Gmail connector can search mail and draft replies, and by default it asks for approval before each send. It sees an attachment’s metadata but not the file itself.
Sending at volume
Each Workspace user can send up to 2,000 messages a day. For office devices and business software, SMTP relay allows up to 10,000 per user per day.
Businesses that send more than 5,000 messages a day to Gmail addresses follow Google’s bulk sender rules: authenticated mail, one-click unsubscribe, and a spam rate kept low.
The Gmail API
The Gmail API reads and sends mail, and manages labels, drafts, filters and delegates. Inside a business’s own Workspace, apps can be authorized organization-wide by an administrator, and internal apps skip the security assessment that public apps with full mailbox access go through.
Rather than checking the inbox on a timer, an integration can get push notifications through Google Cloud Pub/Sub. Each one carries a history ID, and the history API returns exactly what changed since then. The watch is renewed at least once a week.
Since 2025, apps connect to Workspace Gmail with OAuth rather than passwords. Google cancels a connection’s refresh token when the user changes their password, if that connection can read Gmail, so a password reset can stop an invoice import until someone signs in again. Gmail add-ons put custom panels beside an open email, and since July 2025 a single add-on can work across Gmail, Calendar, Drive and Chat.
Turning order and invoice emails into rows
A filter can label every email from a supplier’s address as it arrives, and a push watch can be limited to that label. The integration then hears about invoices and nothing else.
Every message has an immutable ID. An integration that records the IDs it has already turned into rows in Google Sheets can be told about the same email twice and still write one row.
Each supplier lays out an order or invoice in its own way. Pulling the order number and total out of the body takes rules for each sender or an AI step. Emails that match nothing get a label of their own, so someone checks them by hand.
Where the attachments go
The API hands back attachments separately. A message lists each file by name with an ID, and a second request fetches the file itself. In Apps Script, getAttachments() returns all of a message’s files at once, ready to save into a Drive folder named for the supplier or the month.
Gmail next to HubSpot
HubSpot can connect a person’s Gmail as their individual work email, so one-to-one emails go out from the CRM and get logged against the contact. A shared address connects as a team email instead, and one account can’t be both.
When the inbox is the system
Gmail carries a lot of work that other systems should be holding, which leaves plenty to connect. Order and invoice emails can become rows in a sheet or draft bills in the accounts, attachments can file themselves into the right Drive folder, and a customer’s reply can land on their CRM record.
Orders and invoices that arrive by email and get retyped into another system tend to cost more than they look, and a quick sum of the hours involved shows what that retyping costs today.