20 MB EML sample
An EML file of exactly 20,971,520 bytes. It is a valid Email message file, generated by this site. Compare its checksum and test it with the parser used by your application. Use it wherever you need a 20 MB sample, test or dummy EML file.
Download
sample-eml-20mb.eml
20 MB20,971,520 bytes
Download 20 MB EMLCreated in your browser in a few seconds, then checked against the SHA-256 checksum. The file is not uploaded anywhere. No sign-up.
- Type
- message/rfc822
- SHA-256
c924dbef5d8082812ff0b222c2358d83208550fcda60f4ac43d6fbc3203ee837- Delivery
- Created in your browser from static generator assets (how it works).
What is in this file
A plain-text email message with standard headers and 62,682 paragraphs wrapped at 72 characters. Lines of dashes at the end of the body bring the file to the exact size.
| Paragraphs | 62,682 |
|---|---|
| Content type | text/plain, 7bit |
| Attachments | None |
| Line endings | CRLF (RFC 5322) |
| Encoding | UTF-8 (ASCII characters only) |
How the file begins
The opening lines of sample-eml-20mb.eml, exactly as they appear in the file.
00000000 46 72 6f 6d 3a 20 22 53 61 6d 70 6c 65 54 65 73 |From: "SampleTes|
00000010 74 46 69 6c 65 73 20 53 61 6d 70 6c 65 73 22 20 |tFiles Samples" |
00000020 3c 73 61 6d 70 6c 65 73 40 65 78 61 6d 70 6c 65 |<samples@example|
00000030 2e 63 6f 6d 3e 0d 0a 54 6f 3a 20 22 54 65 73 74 |.com>..To: "Test|Preview
Creates the file in your browser and shows the first 64 KB of it.
Where 20 MB matters
A 20,971,520-byte file: right at the default attachment limit of Outlook, and just under the 25 MB ceilings of Gmail and GitHub web uploads. These are the default limits a file of this size is useful for testing:
| System | Limit | Note |
|---|---|---|
| Microsoft Outlook | 20 MB of attachments by default for internet mail accounts | This file is right at the limit; add a second attachment and it is exceeded. |
| Gmail | 25 MB per message | Under the limit, although email encoding adds about a third in transit. |
| GitHub web uploads | 25 MiB per file added through the browser | Accepted. Pushing with Git allows larger files. |
| Cloudflare Pages assets | 25 MiB per file | The largest round size that can be served as a static asset. |
| Amazon API Gateway | 10 MB payload | Rejected; the upload has to go directly to object storage. |
| ASP.NET Core (Kestrel) | About 28.6 MB request body by default | Accepted with room for the multipart overhead. |
Use this file for
- Finding the first upload limit in a new stack
- Testing help-desk and archiving software
- Testing email parsers and import features
Testing notes for EML
- Header values can be folded across lines and encoded with RFC 2047 encoded-words; parsers that read headers line by line get subjects wrong.
- An HTML body is untrusted HTML and needs sanitising before display.
Technical details
| File name | sample-eml-20mb.eml |
|---|---|
| Format | EML (Email message) |
| Extension | .eml |
| MIME type | message/rfc822 |
| Size | 20,971,520 bytes (20 MB) |
| Kind | Text |
| SHA-256 | c924dbef5d8082812ff0b222c2358d83208550fcda60f4ac43d6fbc3203ee837 |
| Created | 2026-10-23 |
| Validation | See the listed size and SHA-256. Small downloads are checked in the browser; verify streamed downloads manually. A hash match does not prove parser compatibility. |
| Preview | Available on this page |
| Source | Generated in your browser by this site's generator; not copied from elsewhere |
| Licence | Free to use, modify and redistribute (terms) |
| Category | Email & Calendar |
Check the stated structure and checksum against your application requirements. As with any download, scan the file with your own security tools before opening it. How files are made and checked
Verify your copy
This file is created in your browser, so it has no direct URL for curl or wget. The generator is designed to produce reproducible bytes. After saving, compare the checksum with the SHA-256 value above.
sha256sum sample-eml-20mb.eml # Linux
shasum -a 256 sample-eml-20mb.eml # macOSOn Windows, run Get-FileHash sample-eml-20mb.eml -Algorithm SHA256 in PowerShell. For scripts and pipelines, save the file once and keep your own copy.
Related files
Questions about this file
- Is this file exactly 20 MB?
- Yes. It is 20,971,520 bytes, which is 20 MB in the binary units that operating systems and server limits use (1 KB = 1,024 bytes).
- What is inside the 20 MB EML file?
- A plain-text email message with standard headers and 62,682 paragraphs wrapped at 72 characters. Lines of dashes at the end of the body bring the file to the exact size.
- Are the email addresses real?
- No. They use example.com and example.org, which are reserved for documentation and cannot receive mail.