# EML Viewer · MSG Viewer & MBOX vs HeaderCheck

The clearest difference is iOS requirement: EML Viewer · MSG Viewer & MBOX at 17.0 against HeaderCheck's 26.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. EML Viewer · MSG Viewer & MBOX sells 3 in-app purchases, starting at $1.00 per 7 days and HeaderCheck sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

EML Viewer · MSG Viewer & MBOX ships an update every 3 weeks, HeaderCheck fortnightly. The most recent releases landed on November 6, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | EML Viewer · MSG Viewer & MBOX | HeaderCheck |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Fortnightly** |
| Size | 18 MB | 2 MB |
| Requires iOS | **17.0** | 26.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Sheenu Jain](https://appshunter.io/developer/6784692835) | [Nicholas McLarty](https://appshunter.io/developer/1572125539) |

## What reviewers say

### EML Viewer · MSG Viewer & MBOX

[App page](https://appshunter.io/ios/app/eml-viewer-msg-viewer-and-mbox/id6795544592)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro (Weekly) | $1.00 | per 7 days |
| Pro (Yearly) | $7.99 | per year |
| Pro (Lifetime) | $9.99 | one-time |


### HeaderCheck

[App page](https://appshunter.io/ios/app/headercheck/id6809026356)

**Features:** macOS Compatibility, Family Sharing, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HeaderCheck Pro | $2.99 | one-time |


## Frequently asked questions

### Is EML Viewer · MSG Viewer & MBOX free?

EML Viewer · MSG Viewer & MBOX is free to download, with in-app purchases available.

### Is HeaderCheck free?

HeaderCheck is free to download, with in-app purchases available.

### Do EML Viewer · MSG Viewer & MBOX or HeaderCheck have ads?

Neither EML Viewer · MSG Viewer & MBOX nor HeaderCheck shows ads.

### Which is updated more often, EML Viewer · MSG Viewer & MBOX or HeaderCheck?

EML Viewer · MSG Viewer & MBOX ships an update every 3 weeks, and HeaderCheck fortnightly. Most recently, EML Viewer · MSG Viewer & MBOX was updated on November 6, 2026 and HeaderCheck on October 31, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*