Comparison

Synology MailPlus vs Instant Guard

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Synology MailPlus

Manage your emails efficiently on mobile with intuitive swipe gestures and quick-reply templates. Organize messages, attach files, and search with advanced features. Requires a Synology NAS and MailPlus server.

Highlights
  • Swipe gestures for quick actions
  • Quick-reply templates
  • Compose and attach files
  • Create mailboxes and labels
  • Advanced search
  • Offline cache for attachments
  • Customizable unread badge
Features
Read full description

**You must own a Synology NAS to run this app, and be running the MailPlus to get the complete set of features** Composing emails or replying to messages on mobile devices can be a hassle. With the intuitive design of MailPlus, you can accomplish more with less effort. Organize your emails right in the palm of your hand. The swipe gestures allow you to quickly apply desired actions to your emails. Quick-reply templates save repeated keystrokes and make your reply even more efficient. With MailPlus, managing emails is only a few taps or swipes away. With MailPlus for iPhone/iPad, you can: -Compose an email and enrich the content with built-in emoticons -Attach files on your mobile device to the message -Create mailboxes and labels -Customize swipe gestures -Use quick-reply templates to reply to emails efficiently -Share browser content with your friends via MailPlus -Customize the unread email badge to only show notifications for certain labels and mailboxes -Find emails efficiently with advanced search -Offline cache stores previously viewed attachments and images for you to browse later even without Internet connection -Supports HTTPS for secure connection -All features are available with DSM 6.0 and MailPlus 1.2.0 running on Synology DiskStation

About

Instant Guard

This app provides a secure VPN connection, allowing you to browse anonymously and protect your financial information on public Wi-Fi. It enables remote access to your home ASUS router, ensuring your privacy and security wherever you go.

Highlights
  • One-click VPN connection
  • Secured and encrypted connectivity
  • Anonymous browsing
  • Change IP address and location
  • Remote ASUS router access
Features
Read full description

Instant Guard is basing on VPN feature of ASUS Router and only available for manager now. Use the Instant Guard app when you connect to public Wi-Fi and just as you are using safety network at home - ensuring your personal privacy remains safe and financial information protected. Instant Guard allows you easily access to your ASUS router at home while you are away and keeps 100% anonymous while you browser bank, shop and chat with Virtual Private Network (VPN) connection. In the future, this feature will improve to allow to share VPN connection permissions to your friends or family members. Key Feature : 1.One-Click Operation 2.Secured and encrypted connectivity 3.Surf Anonymously 4.Change your IP Address and Location *The ASUS routers sold in the CN region do not support Instant Guard. Instant Guard app supports the following ASUS router. RT-BE96U RT-AXE7800 RT-AX92U RT-AX89X RT-AX88U_Pro RT-AX88U RT-AX86U_PRO RT-AX86U RT-AX86S RT-AX82U_V2 RT-AX82U RT-AX68U RT-AX59U RT-AX58U_V2 RT-AX58U RT-AX57_Go RT-AX57 RT-AX56U RT-AX55 RT-AX5400 RT-AX54 RT-AX53U RT-AX52 RT-AC88U RT-AC86U RT-AC3100 RT-AC5300 GS-AX3000 GS-AX5400 GT6 GT-AC2900 GT-AC5300 GT-AX11000 GT-AX11000_PRO GT-AX6000 GT-AXE11000 GT-AXE16000 TUF-AX3000 TUF-AX3000_V2 TUF-AX4200 TUF-AX5400 TUF-AX6000 ZenWiFi CT8 ZenWiFi XD4 ZenWiFi XD5 ZenWiFi XD6 ZenWiFi XP4 ZenWiFi XT9 ZenWiFi AX (XT8) ZenWiFi AX Hybrid (XC5) ZenWiFi ET8 ZenWiFi Pro ET12 ZenWiFi Pro XT12

Screenshots

Synology MailPlus4 screens
Instant Guard4 screens

Verdict

The call

The clearest difference is rating: Synology MailPlus at 3.8 against Instant Guard's 3.4. Instant Guard's advantage is ratings volume (61 vs 19) and iOS requirement (13.0 vs 17.0). On price, review sentiment, update cadence and ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Synology MailPlus holds the better App Store score, 3.8 against 3.4. Both are backed by a comparable volume of ratings — 19 and 61 respectively. Written reviews point the same way: 43% of Synology MailPlus's written reviews are positive against 39% of Instant Guard's.

UpkeepUpdate frequency

Synology MailPlus ships an update every 4 months, Instant Guard every 2 months. Both last shipped on October 24, 2026.

Scorecard3 real differences · 7 level
Synology MailPlus versus Instant Guard: the parameters behind the verdict, then further details
ParameterSynology MailPlusInstant Guard
PriceFreeFree
Rating3.8 (19 ratings) — better3.4 (61 ratings)
Positive reviews42.5% of reviews — better39.3% of reviews
Number of ratings1961 — better
Update frequencyEvery 4 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.013.0 — better
Further details — not scored
Size100 MB64 MB
Age rating4+4+
DeveloperSynology Inc.ASUS

Customer experience

Synology MailPlus

All ratings19 ratings
Positive63.2%
Neutral21.1%
Negative15.8%
Written reviews80 reviews
Positive42.5%
Neutral25.0%
Negative32.5%

Instant Guard

All ratings60 ratings
Positive55.0%
Neutral10.0%
Negative35.0%
Written reviews84 reviews
Positive39.3%
Neutral13.1%
Negative47.6%

Bugs and requests

Synology MailPlus

Not enough reviews yet to summarise bugs or requests.

Instant Guard

Reported bugs

31 issues
  • Auto connection still conflicts
  • Cannot connect after current iOS update
  • Cellular data severely affected
  • Auto protect feature comes on when on cellular network
  • IP Address did not change
Show 26 more
  • App has stopped working
  • No longer works
  • Breaks internet connection completely
  • Useless - Won't connect
  • Stuck at finding router
  • Not a VPN as IP address does not change
  • Auto protect feature ignores settings
  • Share feature simply doesn't work
  • iOS 17 still not working
  • Stopped working after updating
  • Not working with iOS 16.5.1
  • No luck on Mac Studio
  • Won't connect
  • iOS 16.5 incompatible
  • Disconnects every hour or so
  • Can't share connection
  • Connection drops
  • Super buggy app
  • Terrible app with terrible support
  • Worked before, now stopped
  • No ability to share connection
  • Router not detected
  • No Internet connection
  • Kills internet connection
  • Slower upload compared to OpenVPN
  • Router crashed multiple times when connected to WiFi

Requested features

11 requests
  • Add split tunnelling
  • Automatic connection when leaving home network
  • Ability to automatically connect/disconnect based on WiFi network
  • Shortcuts widget for one-touch control
  • Automation capabilities
Show 6 more
  • Family sharing option
  • Set time for VPN disconnection or make disconnection longer
  • Improve auto connect function on iOS
  • Fix auto protect feature on cellular
  • More information on app and web admin page
  • Add option to turn VPN on/off automatically

In-app purchases

None

Synology MailPlus

No in-app purchases

None

Instant Guard

No in-app purchases

Questions

Is Synology MailPlus free?
Synology MailPlus is free to download, with no in-app purchases.
Is Instant Guard free?
Instant Guard is free to download, with no in-app purchases.
Which has better reviews, Synology MailPlus or Instant Guard?
Synology MailPlus is rated higher. Synology MailPlus averages 3.8 out of 5 from 19 ratings, while Instant Guard averages 3.4 from 61 ratings.
Do Synology MailPlus or Instant Guard have ads?
Neither Synology MailPlus nor Instant Guard shows ads.
Which is updated more often, Synology MailPlus or Instant Guard?
Synology MailPlus ships an update every 4 months, and Instant Guard every 2 months. Most recently, Synology MailPlus was updated on October 24, 2026 and Instant Guard on October 24, 2026.

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