Forwarded normally and kept for 30 days
Suitable for standard PDFs, images, spreadsheets, and small archives. A short-term copy is kept in the dashboard to help check delivery, but you should still save needed files in the receiving mailbox.
MESSAGE SIZE / 3 HARD BANDS
Check the full message size first
The limit applies to the encoded message as a whole—not just the attachment size shown in your file manager. As you approach a limit, use a file link instead.
≤50MB: Forwarded and archived50–100MB: Forwarded only>100MB: Rejected
01 / THREE SIZE BANDS
Which path will your email take?
These rules apply to permanent forwarding aliases; temporary inboxes are not designed to store attachments.
Forwarded, but not archived
The receiving mailbox may get the message, but the TmpOne dashboard will not keep a copy. If the receiving provider has a lower limit, delivery may still fail later in the process.
The entire message is rejected
The attachment is not simply removed before forwarding—the entire message is blocked. Ask the sender to reduce its size, split it into several messages, or use a link from a trusted cloud drive.
Temporary inboxes do not retain attachments
Temporary addresses are intended for verification codes, confirmation links, and short text notifications. For reliable file delivery, choose a forwarding alias or a regular mailbox from the start.
Why a 40MB file can become a nearly 50MB message
Email attachments are often encoded with Base64 or similar methods before transmission, which increases their size. Headers, HTML content, inline images, signatures, and multiple attachments also count toward the total message size. The size shown by your file manager therefore may not match the final size received by the server.
Practical buffer: Do not treat 50MB as your file-size target. Once a file reaches roughly 35–40MB, use a file link instead—especially for messages with multiple attachments or rich HTML content.
Compression does not always make files much smaller
Images, videos, PDFs, and existing archives are often already compressed, so putting them in a ZIP may save very little space. Instead of compressing repeatedly, reduce the resolution, split the files, or share a time-limited download link through a trusted platform.
02 / COMMON FILE TYPES
Choose a delivery method by use case
Verification codes and confirmation links
No attachment is needed. A temporary inbox is enough, but do not use it for accounts you may need to recover later.
Contracts and invoices
Use a long-term mailbox or forwarding alias, and back up the files in your own secure storage. Do not rely on the 30-day dashboard archive.
Photos and design files
Multiple high-resolution files can easily exceed the limit. Use a trusted file link and confirm its access scope, download expiration, and deletion options.
Executables and macro-enabled documents
These carry greater risk. Even when the size is within the limit, obtain them from a verified source and scan them with security tools. Never run a file just because the email displays a familiar brand.
How to troubleshoot missing large emails
- Ask the sender for the estimated size of the entire message, not just the attachment.
- Check whether the receiving email provider has a lower limit than TmpOne.
- For messages between 50 and 100MB, look directly in the receiving mailbox instead of checking only the dashboard archive.
- For messages over 100MB, ask the sender to resend them as a link; repeatedly sending the same large attachment will not change the result.
- If a message below the limit is still delayed, use the mail diagnostics console to check the address, status, and sender-side queue.
03 / BETTER CHANNELS
Files never had to travel by email
Email was designed for messages, not file transfer. Switching channels per scenario often solves size and safety in one move.
Send a link, not a copy
A cloud-document link always points at the latest version, and access can be revoked anytime. Once an attachment copy ships, you control neither version nor access.
Direct upload plus an email notice
Deliverables over 50MB belong on a drive or object storage; the email carries only the download link and a checksum. Your recipient's mailbox quota survives too.
A separate encrypted channel
Contracts and identity documents should ride a transfer service with end-to-end encryption and expiry. No email forwarding chain should be the sole carrier of sensitive files.
The disposable inbox is a relay, not storage
Download files received on a temporary address immediately. When the inbox expires, attachments are destroyed with it — there is no second chance.
04 / BEFORE OPENING
Four checks before any attachment lands
The forwarding chain filters out part of the junk, but the last line of defence is always the recipient.
- Verify the sender's full address and domain, not just the display name — display names are freely forgeable.
- Confirm you were actually expecting this file. Unexpected "invoices", "résumés", and "shipping labels" are the most common poison wrappers.
- Read the real extension. "quote.pdf.exe" shows as "quote.pdf" on systems that hide extensions.
- Never open executables or macro-enabled documents directly — scan them first or view them in an isolated environment.