How to Receive Notifications in the iPhone Messages App Triggered by Gmail [Investigation Phase]
I recently signed up for the car-sharing service "Times Car" (formerly Times Car Share), and one thing bothered me while using it.
When you’re on a waiting list for a cancelled or returned vehicle, notifications for available cars arrive via email—but it’s easy to miss emails.
Even when a car becomes available, I often couldn’t react quickly enough and someone else would snap it up.
"Wouldn’t it be much faster if I could get instant notifications on my smartphone, just like an SMS?"
That thought was what sparked my investigation this time.
There are many everyday situations where you want to know immediately when an email from a specific sender or with a specific subject arrives. For example:
- Wanting to know instantly about error emails from a server
- Not wanting to miss messages from family or a boss
- Wanting to receive notification emails from specific services just like SMS
To address these needs, I arrived at the idea of using iPhone automation triggered by Gmail receipt to receive notifications in the iPhone "Messages" app.
This article serves as the "Investigation Phase" summarizing what kind of technical methods are available and how to achieve it for free.
What I Want to Achieve: Gmail → iPhone Messages App
The "Messages app" referred to here is the standard app built into iOS that displays the following types of communication:
- SMS (Short Message Service addressed to a phone number)
- MMS (Carrier email, etc.)
- iMessage (Apple-proprietary communication addressed to an Apple ID or phone number)
The goal is to have notifications arrive automatically in this app whenever a specific email is received in Gmail.
Investigation Result ①: Representative Methods for Email-to-SMS Notifications
Method A: Gmail → Carrier Email (@docomo.ne.jp, etc.)
Japanese mobile carriers provide features that treat email addresses almost like SMS. For example:
| Carrier | Address Example |
|---|---|
| Docomo | xxxxx@docomo.ne.jp |
| au | xxxxx@ezweb.ne.jp, @au.com |
| SoftBank | xxxxx@softbank.ne.jp |
If you send emails from Gmail to these addresses, notifications will arrive in your Messages app looking like SMS.
While it’s actually carrier email rather than true SMS, the notification appearance and behavior are quite similar.
Pros:
- Easy to set up
- Instant notifications
- Completely free
Cons:
- Requires a carrier email subscription
- May get caught in spam filters
- Long messages may get cut off
Investigation Result ②: Sending SMS Using APIs (Twilio, etc.)
By using an SMS API service like Twilio, you can send real SMS to your iPhone triggered by Gmail receipts.
Integrating with Gmail would require IFTTT, Google Apps Script, or a custom script.
Pros:
- Real SMS (carrier-independent)
- Guaranteed delivery to the iPhone Messages app
- Flexible sending based on conditions
Cons:
- Twilio is a paid service ($15 free credit available for first-time users)
- Effort required for phone number registration and API configuration
Investigation Result ③: Sending iMessage via Native Apple Mechanisms
This method involves linking a Mac and an iPhone via iCloud, sending an iMessage from the Mac triggered by Gmail, and receiving it on the iPhone.
Configuration Overview:
Gmail received (specific conditions) ↓ Trigger executed (on Mac) ↓ Send iMessage via Apple Shortcuts or AppleScript ↓ Received in iPhone Messages app
This method can be constructed using purely native Apple mechanisms, and as long as they are synced via iCloud, it works even when you are away from your home LAN.
Required Prerequisites:
- Mac and iPhone logged into the same Apple ID
- iCloud Drive, Messages, and Shortcuts syncing enabled
- Mac powered on and online continuously
- iMessage in a state where it can send messages from the Mac
Investigation Result ④: Completing iMessage Delivery Entirely on the iPhone
As an important point discovered during the investigation, it turns out that you can build the action "send an iMessage notification when a specific email is received" entirely on a standalone iPhone using the automation features of the iPhone "Shortcuts" app.
In other words, you don’t even need a Mac; everything can be completed using just an iPhone linked with Gmail.
What Verification Revealed:
- Email app automation triggers can specify conditions based on "specific sender," "subject," and "account"
- Send iMessage or Notification can be selected under "Actions"
- Automations can be put together in simple steps
- Full automation is possible by turning off "Ask Before Running"
This showed that a very smart notification automation can be achieved for "free," "without OSS," and using "Apple products only."
Comparison with Other Methods
| # | Method | Cost | Difficulty | Implementation | Delivers to iPhone Messages App? |
|---|---|---|---|---|---|
| 1 | Carrier Email Forwarding | ◎ | ★ | Send from Gmail to @docomo, etc. |
◯ (SMS-style notification) |
| 2 | Twilio (SMS API) | △ Free initially |
★★★ | Gmail → API call |
◎ (Real SMS) |
| 3 | Mac + AppleScript + iCloud |
◎ | ★★★ | Call shortcut on Mac side |
◎ (iMessage) |
| 4 | iPhone Shortcuts + Automation |
◎ | ★★ | Configure on iPhone only | ◎ (iMessage) |
Future Outlook: Toward the Configuration Phase
In the next "Configuration Phase," I plan to introduce the actual setup steps in the following order:
- Steps to create an automation in the iPhone Shortcuts app
- How to configure email reception conditions
- Creating the iMessage sending action
- How to prevent it from asking before running
- Advanced applications (sending to multiple recipients, customizing notification content, etc.)
Conclusion
Through this investigation, I initially envisioned a complex setup like "Mac + iCloud + AppleScript + Gmail monitoring," but ultimately arrived at a simple and most practical solution: running automation on the iPhone alone.
In the upcoming configuration article, I plan to introduce the steps along with actual screenshots. Stay tuned!